How Long Would Countries' Oil Stocks Last?

As global oil markets reel from the fallout of the Iran conflict, strategic reserves have once again come into focus as a key buffer against supply shocks. On March 11, 2026, the International Energy Agency and its member countries agreed to release a record 400 million barrels of oil from emergency stockpiles to stabilize markets amid rising prices and disruptions to Middle Eastern supply routes.

IEA member countries are required to hold emergency oil stocks equivalent to at least 90 days of their net oil imports, a rule designed to ensure a coordinated response in times of crisis. In total, members hold more than 1.2 billion barrels of public reserves, alongside roughly 600 million barrels held by industry under government obligation. Notably, the United States is now a net oil exporter (like Canada, Norway and Mexico) and therefore not bound by this requirement. However, the country still maintains the world’s largest emergency stockpile through its Strategic Petroleum Reserve, at about 415 million barrels (as ​of February 27).

Our chart, based on IEA data on oil stock levels, highlights marked differences across countries. Japan and South Korea hold the largest reserves relative to their needs (200 and 208 days, respectively), reflecting their near-total dependence on imported oil and exposure to supply disruptions in the Middle East. European countries also typically maintain reserves well above the IEA minimum, often equivalent to 100 to 200 days of net imports, combining public and industry stocks. At the lower end, Australia (49 days) stands out as the only IEA country well below the 90-day threshold, due in part to limited domestic storage capacity and a reliance on global supply chains, although efforts have been made in recent years to close this gap.