Oil Reserves Monitor · Methodology

The 90-day rule explained: how countries count their oil reserves, and why the day counts differ so much

Illustration of the IEA release mechanism, standing in for the rules behind national oil stock counts

Two bodies set the 90-day benchmark: the International Energy Agency (IEA), which asks for 90 days of net imports, and the EU, whose Directive 2009/119/EC of 14 September 2009 requires the greater of 90 days of average net imports or 61 days of inland consumption in the previous year (Art. 3). Neither counts barrels one for one: crude counts at 96 per cent, a tenth of all stocks is deducted, and many countries add a national formula on top. That is why Japan reports 254 or 214 days for the same stock and why the US, a net exporter, reports its reserve in barrels. Below: the rules, a comparison table and Germany's 91.7 days worked through step by step.

1. How does the EU count its 90 days?

EU Directive 2009/119/EC of 14 September 2009 requires emergency stocks equal to at least 90 days of average daily net imports or 61 days of average daily inland consumption, whichever of the two is greater (Art. 3(1)). The reference is the previous calendar year; from January to March, the year before last is used. For an import-dependent country such as Germany the import test decides; for a country with its own production and therefore small net imports, the consumption test can give the larger figure.

Crude and products are first converted into crude-oil equivalent so they can be added up. On the import side, crude, natural gas liquids and feedstocks are cut by 4 per cent for the naphtha yield and product imports are multiplied by 1.065 (Annex I); consumption uses a factor of 1.2 (Annex II). On the stock side, crude counts at 96 per cent, products at 1.065 or 1.2 depending on the method chosen, and then every stock figure is reduced by a further 10 per cent (Annex III). Crude not yet produced, oil in pipelines, rail cars and filling stations, and military stocks do not count at all.

2. What does the IEA require, and why is the US a special case?

Under the Agreement on an International Energy Program (IEP) of 18 November 1974, IEA members hold emergency oil stocks, and the benchmark the IEA applies today is 90 days of the previous year's net imports. Strictly, the treaty text says 60 days; the Governing Board can raise that level, and 90 days is the standard in use. The IEP also deducts 10 per cent of stocks as unavailable and excludes military stocks and oil on tankers at sea. On top of stocks, each member must be able to cut consumption by 7 per cent at the first stage of an emergency (Art. 5).

Because the IEA test depends only on net imports, net exporters have no obligation: Canada, Mexico and Norway are not required to hold stocks, the IEA says. The US was a net petroleum exporter of 1.64 million barrels a day in 2023 (EIA), yet it keeps the Strategic Petroleum Reserve and reports it in barrels. The Department of Energy equated the 411 million barrels held at the end of 2025 to about 125 days of US crude oil net imports, a count that covers crude only; see US Strategic Petroleum Reserve level. The key difference from the EU is that the IEA has no consumption test, so for producing countries the two day counts can diverge widely. How a collective release works is covered in our glossary entry on the IEA release mechanism, and what was pledged and delivered in 2026 on IEA release 2026: who gave what.

3. Who holds the stocks, and what are tickets?

The 2009 Directive allows each EU country at most one central stockholding entity (CSE), a non-profit body that buys, holds and sells stocks (Art. 7); the UK, outside the EU, has none and places the whole obligation on companies (IEA). Germany's CSE is the EBV, a federal public-law body, which says it owns at least 90 per cent of its stocks. In France companies hand part or all of their obligation to the CPSSP committee, for which SAGESS buys, stores and sells the stocks (French ministry); in Spain industry and the agency CORES share the obligation (CORES).

“Tickets” is the common name for delegated stocks: a company may pass part of its obligation to another operator holding surplus stocks, including in another EU country, if both governments authorise it in advance (Art. 8(1)). Since 31 December 2017 companies must be allowed to delegate at least 30 per cent of their obligation, up from 10 per cent (Art. 8(2)). A country that does not commit to 30 days of “specific stocks”, owned by the state or its CSE, must hold at least a third of its obligation as products (Art. 9).

4. Why does the same oil give different day counts?

Because national rules differ from both the EU and the IEA in their reference period, their denominator or even their unit: the UK, for instance, asks companies for 67.5 days of domestic net consumption rather than 90 days of net imports (IEA, March 2022). That is 61 days plus 10 per cent, at least 22 of them as finished products. Germany averages its net imports over three years (EBV), France sets a share of last year's sales, Spain splits 92 days between industry and CORES, and Switzerland counts months:

MethodBasisExample value, dateSource
EU Directive 2009/119/ECgreater of 90 days of net imports or 61 days of consumption, after deductionsGermany 91.7 days, Austria 88.4 days (June and July 2026)Eurostat
IEA (IEP 1974)90 days of previous-year net imports; stocks minus 10%Japan 214 days (end-2025, IEA basis)METI
United Kingdom67.5 days of domestic net consumption (61 + 10%)no official day count foundIEA
United Statesbarrels in the SPR411 million barrels at end-2025 = about 125 days of crude net imports; net petroleum exporter of 1.64 million b/d (2023)DOE; EIA
Germany, ErdölBevG § 390 days of net imports, three-year average or last year if higherEBV stock 19.7 Mt crude-oil equivalent (31 Dec 2025)EBV
France29.5% of previous-year volumes released for consumptionabout 108 days of consumption (own calculation: 29.5% × 365 = 107.7)French ministry; own calculation
Spain92 days of sales or consumption: 50 industry, 42 CORES (industry share temporarily 4 days lower since 20 Mar 2026)97.1 days on the EU method (June 2026)CORES; BOE; Eurostat
Switzerlandmonths of average demand: 4.5 (petrol, diesel, heating oil), 3 (jet fuel)jet fuel about 76 days (21 Sep 2026)BWL
Japan, Stockpiling Actdays of domestic consumption254 days (end-2025); 199 days (15 Sep 2026)METI

Press figures for France show how far the counts can drift: Public Sénat reported 118 days of net imports on 9 March 2026 and Europe 1 reported 108 days on 12 March, while Eurostat's figure for March is 94.5 days on the EU method. We could not check how either outlet did its sums, and neither figure can be set against Eurostat's. Japan publishes both calculations officially: at the end of 2025 the same stock came to 254 days under the Stockpiling Act, based on domestic consumption, and 214 days on the IEA basis, which includes LPG. What any day count leaves out is explained under days of supply.

5. Worked example: how does Germany reach 91.7 days?

Eurostat puts Germany at 91.7 days in June 2026, and that does not clash with the 19.7 million tonnes of crude-oil equivalent the stockholding agency EBV reported for the end of 2025: the two figures measure different things at different dates. Here is how the day count is built:

  1. Denominator: Eurostat uses average daily net imports of 207.572 thousand tonnes for Germany (January to June 2026; 206.743 in December 2025).
  2. Obligation: Eurostat's calculated minimum stock is 18,681.469 thousand tonnes; divided by 207.572 that is 90.0 days (own calculation).
  3. Numerator: emergency stocks are counted under Annex III, crude at 96 per cent, products at 1.065 or 1.2, then minus 10 per cent.
  4. Result: countable stocks divided by daily net imports give 91.7 days, slightly above the obligation.

Dividing the EBV's 19.7 million tonnes (10.8 crude, 1.7 petrol, 4.5 diesel, 1.5 heating oil, 1.2 jet fuel) by 207.572 would mislead: the figure dates from 31 December 2025, before the March release; crude-oil equivalent is the EBV's own measure, and its publication does not say whether or how the Directive's deductions are included; and the Directive allows compulsory stocks to be held in other EU countries. Current day counts for every country are on the Oil Reserves Monitor overview, the basics in our glossary entry on the Strategic Petroleum Reserve.

How to cite: Global Oil Shock (Jörg Dässler), “IEA 90-Day Rule: How Oil Reserve Days Are Counted”, as of 23 Sep 2026, https://globaloilshock.com/en/strategic-oil-reserves/90-day-rule/

6. Frequently asked questions about the 90-day rule

What is the IEA 90-day oil stock rule?
Each IEA member must hold oil stocks equal to at least 90 days of the previous year's net imports, with 10 per cent deducted as unavailable. The basis is the International Energy Program agreement of 1974, whose text sets 60 days and lets the Governing Board raise the level; the IEA applies 90 days (IEP; IEA). Net exporters have no obligation.
How are oil reserve days calculated?
Countable emergency stocks are divided by average daily net imports, or, in the EU, by consumption if that gives the larger obligation. Under the EU Directive crude counts at 96 per cent, products are converted with factors of 1.065 or 1.2, and 10 per cent of everything is deducted (Directive 2009/119/EC, Annex III).
Does the US have to hold 90 days of oil?
In practice, no. The IEA's obligation depends on net imports, and the IEA exempts net exporters such as Canada, Mexico and Norway. The US was a net petroleum exporter of 1.64 million barrels a day in 2023 (EIA), so the import test gives it no 90-day figure in the usual sense. It still keeps the Strategic Petroleum Reserve and reports it in barrels; the DOE put the 411 million barrels held at the end of 2025 at about 125 days of crude oil net imports.
How many days must the UK hold?
67.5 days of domestic net consumption, which is 61 days plus 10 per cent, with at least 22 days as finished products; the obligation falls on companies supplying more than 50,000 tonnes a year (IEA). The UK has no central stockholding agency and publishes no exact day count.
Why does Japan report 254 and 214 days for the same stock?
Because METI publishes both calculations: under Japan's Stockpiling Act, based on domestic consumption, it was 254 days at the end of 2025; on the IEA basis, which also counts LPG, it was 214 days. On 15 September 2026 METI's national quick estimate showed 199 days.

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