Worldscale Explained: Tanker Freight Rates and WS100

Worldscale, the Worldwide Tanker Nominal Freight Scale, is the standardized nominal freight-rate scale of the tanker market, published annually by the Worldscale Associations of London and New York, on which “WS100” (the flat rate) is the reference cost in US dollars per tonne of moving oil over a given route, and actual freight is quoted as a percentage of it. It is a standard of reference rather than a price list. The Associations calculate, for the carriage of oil in bulk by a single nominal “standard vessel,” the freight per tonne that would just cover the cost of each specific voyage. That break-even figure is defined as WS100. Owners, charterers and brokers then fix the real freight as a percentage of it, so a strong crude market might trade at WS90 and a tight products market at WS250.

The value of that convention is comparability. A tanker fixture from the Middle East Gulf to China, another from West Africa to Rotterdam, and a third across the Mediterranean each have different distances, port costs and canal exposure, so their freight in dollars per tonne is not directly comparable. Expressed as a Worldscale percentage, they sit on one scale, and a broker can read the market at a glance. By 2002 the schedule already covered around 320,000 voyage permutations, from one load and one discharge port up to five loads and ten discharge ports, which is why no voyage charter party for a tanker needs to attach its own freight table.

This article explains what Worldscale is and is not, how a WS percentage converts into money, how the Associations build the flat rates from the standard vessel and its cost assumptions, how the scale reached its present form through the 1969 unification and the New Worldscale re-basing of 1989, and how a Worldscale rate feeds the Time Charter Equivalent that owners actually use to judge a voyage. It covers the tanker-market context, the Baltic Exchange indices that report rates on a Worldscale basis, and the practitioner errors that recur around WS100.

What Worldscale is

Worldscale is a schedule of nominal freight rates for the carriage of crude oil and oil products in bulk by sea. Its defining word is “nominal.” The published rates are a common baseline against which the market negotiates, not rates anyone is expected to charge. The scale’s governing principle, set out in its Preamble, is to give the standard-vessel owner the same net return per day irrespective of the voyage performed, at WS100. Because each route’s flat rate already absorbs that route’s distance, bunker burn, port charges and canal dues, a single percentage carries the same commercial meaning everywhere on the scale.

It is published jointly by two non-profit-making bodies: Worldscale Association (London) Ltd, which covers the rest of the world, and Worldscale Association (NYC) Inc., which covers the Americas. Each is run by a management committee drawn from the senior tanker brokers of its city, and access to the schedule is by subscription, taken by shipowners, oil companies, traders and broking houses. The scale is not a market forecast and does not set rates; it is a passive reference that the freight market prices against day by day.

Worldscale is a tanker-only convention. It applies to liquid bulk, both dirty cargoes (crude and residual “black” oils) and clean cargoes (clean petroleum products such as gasoline, jet, naphtha and condensate). It has no counterpart in dry bulk, where freight is quoted directly in dollars per tonne or as a time-charter rate in dollars per day. A reader coming from the dry trades, where the Baltic Dry Index and freight indices frame the market, should not expect a percentage scale on the dry side; there isn’t one.

Reading a Worldscale quote and converting it to money

A fixture is agreed at a Worldscale percentage, written as “WS” followed by the number: WS100 is the flat rate itself, WS150 is 150 per cent of it, WS75 is 75 per cent, and in extreme markets quotes have ranged from single figures to WS1000. The percentage is the whole of the negotiation. Everything else, the dollars-per-tonne baseline for that particular route, is already fixed by the published flat.

To turn a Worldscale level into a cash freight rate, multiply the route’s flat rate by the percentage over 100.

So a route with a flat rate of USD 10.00 per tonne fixed at WS120 pays USD 12.00 per tonne, and the gross freight is that figure multiplied by the cargo quantity. From gross freight the owner deducts address commission and brokerage, commonly in the range of 1.25 to 3.75 per cent combined, to reach net freight. The freight the charter party actually references is the Worldscale level plus the agreed commission terms, not a dollar figure, which is exactly the economy the scale was built to provide.

A clean-products example makes the arithmetic concrete at the other end of the fleet. Take an MR product tanker lifting 37,000 tonnes of gasoline from the Middle East Gulf to Japan, and assume an illustrative flat rate of USD 34.00 per tonne fixed at WS180. The rate is USD 34.00 multiplied by 180 over 100, or USD 61.20 per tonne. Gross freight is 37,000 tonnes at USD 61.20, or USD 2,264,400. The clean number sits at a far higher Worldscale level than a crude VLCC fixture, because a smaller ship at 37,000 tonnes has a much higher flat-rate-implied cost per tonne of cargo than the 75,000-tonne standard vessel, and the market lifts the percentage to make the economics work. The dollars-per-tonne figures on the two trades look nothing alike, yet both are read off the same scale.

The percentage is not, by itself, a measure of profit. WS100 is a break-even only for the nominal standard vessel described below, so a modern ship of a very different size earns a very different result at the same WS number. Two fixtures at WS150 on different routes, or the same route in different years, can mean quite different money. That is why a Worldscale level is a starting point for the real calculation, not the end of it, and why owners convert every voyage to a Time Charter Equivalent before comparing it with anything else.

One more piece of vocabulary belongs here. A move of one percentage point on the scale is a “Worldscale point,” and brokers talk in points when they describe how a market has moved: a route that firms from WS90 to WS110 has gained twenty points. Because a point is one per cent of that route’s flat rate, the cash value of a single point differs from route to route and from year to year, which is another reason the same point move can mean very different money on a long crude haul and a short clean run. On a route with an USD 18.00 flat, one point is worth USD 0.18 per tonne, or on a 260,000-tonne cargo about USD 46,800 of gross freight; on a route with an USD 6.00 flat it is worth USD 0.06 per tonne. The point is a unit of the scale, not a unit of money.

The standard vessel and the flat-rate basis

The flat rates rest on a single nominal ship and a defined set of cost assumptions, all stated in the Preamble to each annual edition. Under the New Worldscale basis in force since 1989, the standard vessel and its inputs are:

Every one of these figures is nominal, used only to compute the flat rates. The Preamble is explicit that the USD 12,000 per day hire element does not represent any real ship’s operating cost and guarantees no owner a margin; it is a calculation constant. For each specific voyage the Associations work out the round-voyage time at 14.5 knots over the cheapest route, apply the bunker consumptions at the edition’s assessed fuel price, add the port charges and any canal dues, add the fixed hire over that time, and divide the total by the cargo the standard vessel would carry. The resulting freight per tonne is WS100 for that route.

The distinction between what is revised and what is held constant is the key to reading the scale over time. Each January edition uses fresh bunker prices, port costs and currency exchange rates assessed up to the previous 30 September, and, since the 2025 edition, an EU ETS carbon cost priced off ICE EUA futures settlements averaged over the same 1 October to 30 September window. The new schedule is published in November and takes effect on 1 January. The bunker input changed with the fuel: from the 2020 edition it moved to compliant 0.50% sulfur residual fuel, following the MARPOL Annex VI Reg.14 limit that applied from 1 January 2020, with the September 2019 VLSFO average used as a one-off before the October to September averaging resumed. The standard vessel and the USD 12,000 per day hire are deliberately not changed, so movement in the flat rates from one year to the next reflects the movement in costs, above all bunkers, rather than a change in the method. A subtle but important point sits inside the distance assumption: the flat uses the cheapest route including canal and pilotage fees, which is not always the shortest, because a canal saving in distance can be outweighed by its dues.

Costs that the standard voyage does not capture are handled through differentials, published in the section brokers call the Pink Pages. The distinction between the two kinds matters in a fixture. A fixed differential is a set amount in dollars per tonne, added to or subtracted from the flat rate before the Worldscale percentage is applied to the base voyage, and it is used where a cost is broadly the same whatever the state of the market: an additional load or discharge port, a lightering operation at anchor, a particular canal or pilotage situation, or the extra steaming to a berth outside the nominal port. A variable differential, by contrast, is expressed in Worldscale terms and moves with the agreed percentage, so it captures a cost that scales with the freight level itself. The distinction is not academic: applying a canal or extra-port cost as a percentage of a WS250 clean fixture rather than as a fixed sum would overstate it several times over, so the Pink Pages set out, route by route, which treatment applies.

The differential machinery is what lets one flat rate per route serve a wide range of real itineraries without a separate calculation for every variation. A charterer nominating a second discharge port, a ship instructed to lighten part of a crude cargo into a smaller vessel before entering a draught-restricted port, or a voyage routed via the Suez Canal rather than the Cape all draw on published differentials rather than a bespoke flat. The freight clause in the charter party therefore reads as “Worldscale” plus the agreed percentage, with the differential terms folded into the settlement, and the arithmetic of the final freight follows the Preamble rather than a private negotiation over dollars per tonne.

The schedule and the annual cycle

The published book is organized as a vast matrix of port-to-port flat rates, together with the Preamble that sets the basis of calculation, the differential tables, and the port and canal cost data behind the rates. Its scale is easy to underestimate: the Associations put the book at roughly 300,000 rates a year, and take enquiries for itineraries of up to five load ports and ten discharge ports, so that almost any itinerary a charterer might construct already has a published flat. This coverage is the practical reason a tanker voyage charter party can settle its freight in one line. The alternative, a bespoke rate table negotiated and attached to every fixture, is exactly what the scale was created to abolish.

The cycle that keeps the book current runs to a fixed calendar. Cost inputs, above all bunker prices, port costs and currency exchange rates, are gathered and assessed up to 30 September; the Associations recompute every flat rate on the new inputs while holding the standard vessel and the fixed hire element constant; the new edition is published in November and takes effect on 1 January. The flat rates are recomputed in full only once a year, which is what makes a within-year Worldscale series comparable and a cross-year one not, but they are not sealed between editions: the Associations amend individual rates and differentials by circular where costs move sharply, as they did for Ras Tanura, Juaymah and Ras Al Khafji for voyages loading on or after 1 May 2017. A subscriber reads the current year’s flat for a route straight from the book and applies the market percentage to it; when the calendar turns, the same route’s flat may step up or down with the change in costs, and the market’s WS level shifts to keep the cash freight roughly where supply and demand put it. Because access is by subscription and the Associations are non-profit bodies run by broker committees rather than a commercial index vendor, the schedule sits as shared market infrastructure rather than a proprietary data product, which is part of why it has held its central role for so long.

From Worldscale to Time Charter Equivalent

A Worldscale percentage cannot be compared directly across routes, because each route carries its own flat rate and its own real voyage costs. Owners resolve this by converting every voyage to a common Time Charter Equivalent, or TCE, expressed in dollars per day. The TCE takes the voyage’s gross freight, subtracts the actual voyage expenses, bunkers, port charges and canal dues, and divides by the voyage days, and those days include the ballast leg on which the ship earns nothing.

That ballast leg is the reason a round-voyage TCE always falls below the naive one-way figure implied by the freight. The Worldscale rate pays for the laden passage; the empty positioning voyage to the load port is absorbed into the denominator of the TCE, never into the rate. Two fixtures at the same WS level therefore produce different TCEs whenever their ballast legs, canal exposure or port time differ. The same WS level even earns different money in different years, because bunker prices move daily and sit on the cost side of the TCE, while the flat rate is reset only once a year. A rise in fuel between January editions eats into the TCE at an unchanged Worldscale level.

The mechanics of that conversion, together with bunker and canal economics, are set out in voyage estimation . The practical takeaway for reading Worldscale is that the percentage is an input to the owner’s real number, not the number itself. A chartering desk that judged fixtures on the WS level alone, without running the TCE, would systematically misprice long-ballast and canal-heavy voyages.

Worldscale in the spot tanker market

Worldscale is the standard basis for single-voyage, or spot, tanker fixtures. The charter party, most often the ASBATANKVOY form for crude and a small family of clean-products forms, sets the freight as “Worldscale” plus the agreed percentage and commission, and leaves the dollars-per-tonne detail to the published flat. The same convention runs across both the dirty and the clean trades, which the market and the indices keep separate because their vessels, cargoes and rate levels differ.

A worked example shows the flow. Take a VLCC lifting 260,000 tonnes of crude from the Middle East Gulf to China, and assume a published flat rate of USD 18.00 per tonne for the route, which is illustrative because the real flat changes each edition, fixed at a market level of WS55. The rate is USD 18.00 multiplied by 55 over 100, or USD 9.90 per tonne. Gross freight is 260,000 tonnes at USD 9.90, or USD 2,574,000. From that the owner deducts commission, subtracts the actual bunkers, port charges and any canal dues, and divides the remainder by the round-voyage days, including the ballast passage back toward the loading area, to reach the TCE in dollars per day that tells the owner whether the fixture was worth taking.

The size of the ship matters to how that WS level reads. The standard vessel is 75,000 tonnes, roughly Aframax scale, so a VLCC of around 300,000 tonnes deadweight carries far more cargo against broadly similar port and crewing overheads and enjoys strong economies of scale. At the same Worldscale number a larger tanker generally earns a better result per tonne of capacity than the standard vessel, and a smaller one a worse result, which is one reason clean-products rates on 35,000 to 55,000 tonne ships routinely trade at much higher WS numbers than crude rates on VLCCs. The scale is one number; the economics behind it depend on the ship carrying the cargo, and the tanker size classes article sets out where the standard vessel sits among them.

Economies of scale and the standard vessel

Because the flat rate is built for a 75,000-tonne ship, the relationship between the Worldscale level and a real ship’s earnings depends heavily on how far that real ship departs from the standard. This is the single most important thing to understand about reading WS numbers across the fleet, and it explains a pattern that puzzles newcomers: why crude VLCC rates are quoted in double-digit WS numbers while clean MR rates on the same water can trade at WS200 or more.

The mechanism is straightforward. The flat rate for a route recovers the standard vessel’s round-voyage cost, dominated by the fixed hire element and the bunkers, spread over the standard vessel’s cargo intake. A VLCC carries roughly four times the standard vessel’s cargo, but its bunker burn is not four times as high and its port and crewing overheads are broadly similar, so its cost per tonne of cargo carried is far below the standard vessel’s. At WS100 the VLCC would earn well above the nominal daily return, and the market corrects for this by trading crude VLCC business at low WS numbers, often well below WS100, while the ship still earns a healthy TCE. A 37,000-tonne MR runs the opposite way: it carries half the standard vessel’s cargo against similar fixed costs, so its cost per tonne is higher, WS100 leaves it short, and the market lifts the clean percentage to compensate.

A stylized contrast makes the point without pretending to be a live quote. Suppose a crude route has a flat of USD 18.00 per tonne and a clean route on similar water has a flat of USD 34.00 per tonne. A VLCC fixed at WS55 on the crude route earns USD 9.90 per tonne; an MR fixed at WS180 on the clean route earns USD 61.20 per tonne. The clean ship’s headline WS number is more than three times the crude ship’s, and its dollars per tonne more than six times as high, yet after each ship’s very different cargo size, bunkers and voyage length are put through the TCE calculation the two daily earnings can end up in the same broad region. The Worldscale level alone tells you almost nothing about which fixture earned more; only the TCE does. This is why a chartering desk never compares a crude WS number with a clean WS number directly, and why every rate history that spans ship sizes is drawn in dollars per day, not in points of scale.

The Baltic Exchange tanker indices

The daily tanker market is reported through the Baltic Exchange, which collects rate assessments from a panel of brokers for a set of defined routes and publishes them on both a Worldscale basis and a Time Charter Equivalent basis. The route assessments roll up into two headline benchmarks: the Baltic Dirty Tanker Index (BDTI) for crude and residual oils, and the Baltic Clean Tanker Index (BCTI) for clean products. These indices, and the wider family of freight benchmarks, are described in Baltic Dry Index and freight indices , which despite its dry-bulk title covers the tanker indices alongside the dry ones.

The route codes are the working vocabulary of the market. On the dirty side, TD3C is the flagship VLCC benchmark, 270,000 tonnes Middle East Gulf to China; TD20 is a key Suezmax route, 130,000 tonnes West Africa to UK-Continent. On the clean side, TC7 covers 35,000 tonnes Singapore to East Coast Australia, and the BCTI headline basket is built from a set of clean routes that the Baltic Exchange revises from time to time. Because the Exchange assesses each route in Worldscale terms as well as in TCE, the two conventions sit side by side: the WS level shows where the route is trading against its nominal flat, and the TCE shows what that means in daily earnings for a representative modern ship on the route. Anyone quoting a specific current route basket or weighting should confirm it against the live Baltic Exchange route material, because the definitions are periodically revised.

Worldscale also underpins the tanker freight-derivatives market. Forward freight agreements on tanker routes are quoted and settle on a Worldscale basis, with the settlement referencing the relevant Baltic assessment, so the same nominal scale that prices a physical fixture also prices the paper hedge against it.

How the market uses Worldscale in practice

For a chartering desk, Worldscale is the shorthand that keeps a fast market legible. When a cargo comes to the market, the charterer’s broker circulates it with the load and discharge ranges, the laydays, the quantity and the ship requirements, and offers come back as Worldscale numbers. An owner comparing three enquiries, a crude stem out of the Gulf, a fuel-oil cargo in the Mediterranean and a naphtha parcel in the Far East, is not comparing three dollars-per-tonne figures with different underlying distances and costs; the desk reads the WS levels against where each route has recently traded, forms a view on each in TCE, and decides which to chase. The scale turns a heterogeneous set of voyages into one comparable market, which is the reason it has survived unchanged in principle since 1969.

The reporting rhythm reinforces this. The Baltic Exchange panel assesses the benchmark routes daily in Worldscale terms, brokers publish fixture reports that quote the WS level of each reported deal, and market commentary describes movements in points. A trader who reads that “TD3C firmed ten points on the back of a fresh cargo list” has learned something precise about the crude VLCC market without any dollar figure changing hands. The annual reset then sits underneath all of this: on 1 January the flat rates change, so the same market strength shows up at a different WS number than it would have under the previous edition, and analysts who track rates across a year-end have to convert to a common basis, almost always TCE, to see through the reset.

The physical and paper markets share the convention. A shipowner worried about a soft second quarter can sell a forward freight agreement on a tanker route at a Worldscale level; if the physical market weakens, the loss on the ship’s fixtures is offset by the gain on the paper, because both are struck against the same Baltic Worldscale assessment. Charterers and trading houses use the same instruments in reverse to lock in a freight cost. None of this would be workable if each route were quoted in its own dollars-per-tonne terms; the single percentage scale is what lets a physical fixture and its hedge speak the same language.

History: from wartime schedules to New Worldscale

Worldscale grew out of the tanker requisitioning of the Second World War, when the British and later the United States governments took tankers into service and compensated owners on a daily-hire basis, making ships available to the oil majors at rates set by government schedules. When control ended, non-governmental bodies took over the work of publishing reference rates, and through the 1950s two competing systems emerged. London issued a series of scales and then Intascale; New York issued the American Tanker Rate Schedule, ATRS. The London scale was established in November 1952 by the London Tanker Brokers’ Panel at the request of British Petroleum and Shell.

The decisive step came in 1969, when the London and New York bodies replaced both Intascale and ATRS with a single global scale, the Worldwide Tanker Nominal Freight Scale, code-named Worldscale, effective from September 1969. From that point the market expressed rates as a direct percentage, the “points of scale,” of one published reference. This “Old Worldscale” ran from 1969 to 1988. It was revised regularly for bunker prices and port costs, but its fixed daily hire element of USD 1,800 was held constant throughout, a figure that traced back through the 1969 exchange rate of one pound to 2.40 dollars to the sterling hire of the older Intascale.

Two forces pulled the old basis out of shape over its two decades. The bunker-price shocks of the 1970s repeatedly swung the fuel component of the flat rates while the fixed hire stayed frozen at a figure rooted in a 1960s exchange rate, so the balance between the fixed and variable parts of the flat drifted away from the economics of the ships actually trading. At the same time the fleet had changed out of recognition, with the very large crude carrier now the workhorse of the long-haul crude trades, far from whatever nominal ship the 1969 basis implied. A flat rate whose fixed element no longer reflected any real daily cost, and whose standard ship no longer resembled the fleet, made the WS numbers harder to read against real earnings.

By the late 1980s the USD 1,800 basis had drifted far from the realities of the trade, and after a lengthy study the Associations re-based the whole system. New Worldscale took effect on 1 January 1989, built on the 75,000-tonne standard vessel and the USD 12,000 per day fixed hire element described above, and moved to the fixed-hire-plus-variable-cost method still in force. The epithet “new” was soon dropped in ordinary use: today “Worldscale” means the current scale, and the pre-1989 system is referred to as Old Worldscale when the distinction matters, for instance when comparing rate levels across the 1989 boundary, which are not directly comparable because the basis changed.

Worldscale and dry bulk: why the scale is tanker-only

It is worth stating plainly, because it is a common point of confusion, that Worldscale does not touch the dry-bulk trades. Dry cargoes are fixed either as a voyage rate in dollars per tonne or as a time charter in dollars per day, and the market is tracked by the Baltic Dry Index and its capesize, panamax, supramax and handysize sub-indices. There is no nominal-percentage scale in dry bulk analogous to Worldscale, and no “WS” number is ever quoted for a bulk carrier. The reason is partly historical, the tanker scale grew from the oil majors’ need to compare a small number of very standardized liquid trades, and partly structural, the dry trades cover a far wider range of commodities, stowage factors and parcel sizes that resist a single standard-vessel abstraction. A charterer moving between the two markets has to switch conventions entirely: percentage of a nominal flat on the wet side, dollars per tonne or per day on the dry side.

Common errors and practitioner caveats

Several misreadings of Worldscale recur often enough to be worth naming directly.

The first is treating WS100 as a rate. It is the nominal reference, the published flat, not a market price; the market price is the negotiated percentage of it. A statement that “the rate is Worldscale 100” describes the benchmark, not a fixture.

The second is assuming that a Worldscale level means the same money over time. Because the flat rates are recalculated every January, WS100 on a route in 2026 is a different figure in dollars per tonne than WS100 on the same route in 2024. Comparing historical Worldscale levels in cash terms without applying each year’s flat rate is a straightforward error, and it is the reason long-run rate charts are usually drawn in TCE, not in WS.

The third is imagining that the standard vessel is a real ship. The 75,000 tonnes and USD 12,000 per day are calculation inputs; actual fixtures involve VLCCs, Suezmaxes, Aframaxes and product carriers whose economics differ sharply from the nominal ship, which is exactly why the same WS number reads differently across sizes.

The fourth is equating a higher Worldscale level with profit. At low WS levels a fixture can produce near-zero or negative Time Charter Equivalent earnings once real bunkers, port charges and the unpaid ballast days are counted, so profitability must be judged in TCE. A ship can be fixed at a positive Worldscale number and still lose money on the round voyage.

The fifth is assuming the flat rate is built on the shortest route. It is built on the cheapest route including canal and pilotage dues, and the cheapest route is not always the shortest when a canal saving in distance is outweighed by its transit cost.

The sixth is expecting Worldscale to set or predict rates. It does neither. It is a passive standard of reference; the market sets the percentage, and the scale simply provides the common denominator. Its role is to make thousands of routes comparable and to keep the freight clause in a voyage charter party to a single line, not to signal where rates should be. Related mechanics, the counting of allowed time under laytime and the charge for overrunning it under demurrage , sit alongside the freight in the same fixture but are governed by their own clauses, not by the Worldscale schedule.

Related Articles

• Voyage charter party
• Voyage estimation: TCE, bunkers, and canal economics
• Baltic Dry Index and freight indices
• Forward freight agreements
• Tanker size classes: MR to ULCC
• Oil tanker
• Laytime
• Demurrage
• Charter parties: voyage, time, and bareboat
• Average Freight Rate Assessment (AFRA)