307.7m barrels
U.S. SPR · 2026-07-24
Calculator based on official formulas
How Long Would Oil Reserves Last? SPR and IEA 90-Day Calculator
Calculate a nominal U.S. SPR drawdown duration from the latest EIA stock and DOE release limit, then separately test the IEA's 90-day net-import-cover formula.
EIA reference 2026-07-24 · DOE and IEA sources reviewed 2026-07-31
DIRECT ANSWER
Dividing the current U.S. SPR by the maximum nominal rate gives about 70 days
The EIA reports 307.7 million barrels in the SPR for the week ending July 24, 2026. Dividing that by the DOE's maximum nominal drawdown capability of 4.4 million barrels per day gives 69.9 days. This is not the number of days the United States can run without oil, nor a guarantee that the same delivery rate can be sustained.
Stock divided by release rate and IEA net-import cover answer different questions. The calculators keep the two results separate.
4.4m b/d
DOE maximum nominal rate
About 70 days
Simple division
90 days
IEA minimum net-import cover
Nominal U.S. SPR drawdown duration
This is the simple result of stock divided by daily release. It is not a measure of U.S. energy independence or actual supply duration.
Nominal drawdown duration
69.9 days
- Latest EIA weekly value
- 307.7 million barrels
- DOE maximum nominal rate
- 4.4 million barrels/day
Actual delivery can be lower as inventories decline or because of pipelines, ports, refineries, buyer acceptance, and policy decisions.
IEA net-import cover
This simplifies the IEA's core formula: eligible emergency reserves divided by daily net imports. A 10% deduction for unavailable stocks is applied first.
- Eligible reserve after 10% deduction
- 90m
- Net-import cover
- 90 days
- Gross stocks needed for 90 days
- 100 million barrels
At least 90 days for these inputs
Deduction used in this simplified model: 10%
A formal IEA assessment also adjusts prior-year net imports, naphtha, refined products, stocks held abroad, and bilateral arrangements. This result alone cannot determine compliance.
Why there are two different formulas
Nominal U.S. SPR drawdown duration
SPR inventory ÷ daily release
A simple duration assuming a constant release rate. It excludes domestic production, commercial stocks, imports, refining, and transport constraints.
IEA days of net-import cover
Eligible emergency reserves ÷ prior-year average daily net imports
The basis for IEA member stockholding obligations. Formal assessment adds crude-product conversions, deductions, and stocks held abroad.
Official evidence used by the calculator
Latest U.S. SPR inventory
307.7 million barrels
U.S. SPR drawdown capability
Maximum nominal 4.4 million barrels/day
IEA minimum stockholding obligation
Prior-year average daily net imports × 90
Conditions that must stay attached to the result
- ✓ The U.S. SPR holds crude oil; it is not the same as immediately available gasoline or diesel.
- ✓ The DOE's 4.4 million b/d figure is a maximum nominal capability. The rate may decline with inventory.
- ✓ The roughly 13-day delay before oil enters the U.S. market is a separate timing constraint.
- ✓ Actual delivery needs pipelines, ports, refiners, compatible crude grades, and buyer acceptance.
- ✓ The IEA's 90 days means net-import cover, not 90 days of total oil consumption.
- ✓ This simplified result cannot determine a member country's formal compliance.
Frequently asked questions
How many days would the U.S. Strategic Petroleum Reserve last?
At 4.4 million barrels per day, the July 24, 2026 inventory produces a simple 69.9-day result. Actual duration differs with declining release rates, domestic production, imports, commercial stocks, refining, and transport.
Does the IEA's 90-day obligation mean 90 days of all oil demand?
No. It is based on the previous calendar year's average daily net imports. It is an import-security metric, not 90 days of total consumption.
Why does the calculator deduct 10% from stocks?
The IEA applies a 10% deduction for unavailable stocks such as tank bottoms. Formal methodology also adjusts primary and refined products.
Is 307.7 million barrels the latest U.S. SPR value?
This page uses the EIA value for the week ending July 24, 2026 and displays that reference date beside the result.
Open the original sources
- EIA inventory date
- 2026-07-24
- Time to market
- 13 days
- IEA deduction
- 10%