Which Countries Hold the Largest Proven Oil Reserves, and What Share of the World Does Each Control?

Venezuela leads, but three Gulf producers sit close behind

Short answer: the country with the largest proven oil reserves is Venezuela, with 303.7 billion barrels at the end of 2025, or 19.3 percent of the world total of 1,572 billion barrels. Saudi Arabia is second with 267.2 billion barrels (17.0 percent), Iran third with 208.6 billion (13.3 percent), Iraq fourth with 140.0 billion (8.9 percent) and the United Arab Emirates fifth with 120.0 billion (7.6 percent). These are the figures published by OPEC in its Annual Statistical Bulletin 2026, the most widely used official ranking of proven crude oil reserves.

Kuwait (101.5 billion barrels), Russia (80.0 billion), Libya (48.4 billion), the United States (41.9 billion) and Nigeria (37.0 billion) complete the top ten. The list has an obvious geographic pattern: six of the ten largest holders are in the Middle East or North Africa, and only two, Russia and the United States, are outside OPEC. The 20 countries in the chart below hold 1,498 billion barrels, 95.3 percent of all proven crude oil on the OPEC list, which leaves just 74 billion barrels for every other country combined.

One country, one fifth: Venezuela alone holds 19.3 percent of world proven crude oil, more than the 13 countries ranked 8th to 20th combined.

Proven reserves are not the same as all the oil in the ground. They are the volumes that the reporting country or company says can be recovered with reasonable certainty from known fields, using current technology and at current prices. OPEC compiles the table from figures submitted by governments and national oil companies, and several of those figures have barely moved for years. Kuwait has reported 101.5 billion barrels, Libya 48.4 billion, Qatar 25.2 billion and Kazakhstan 30.0 billion in every year from 2017 to 2025 in the OPEC tables. For the industry behind these barrels, including production, demand and the largest companies, see our global oil industry statistics.

Oil reserves by country: the full top 20 with shares of the world total

The table lists the 20 largest holders of proven crude oil reserves at the end of 2025 as published by OPEC, with each country share of the world total and its OPEC status. The last column flags the countries where the OPEC figure differs most from other official or company sources, a point explained in detail further down.

Source: OPEC Annual Statistical Bulletin 2026, Table 3.1 (data at 31 December 2025). Shares calculated by BusinessStats from the OPEC world total of 1,572.459 billion barrels. OPEC status refers to membership on 31 December 2025; the UAE left OPEC on 1 May 2026.

Two names that many readers expect are not in the OPEC top 20, or sit near the bottom of it. Canada appears in 20th place with 5.1 billion barrels because OPEC records only its conventional crude, not the bitumen in the Alberta oil sands. Guyana is not listed separately in the OPEC table at all, while Eni puts its reserves at 11.0 billion barrels. China, by contrast, climbed into 11th place after its reported reserves rose from 28.2 billion barrels at the end of 2024 to 34.5 billion at the end of 2025, one of the largest upward revisions in the 2026 edition.

The top ten hold 85.7 percent of all proven crude oil

Oil reserves are far more concentrated than oil production or consumption. On the OPEC figures, the top three countries alone hold 779.5 billion barrels, which is 49.6 percent of the world total. The top five reach 1,039.5 billion barrels and 66.1 percent. The top ten hold 1,348.3 billion barrels, or 85.7 percent, and every other country in the world shares the remaining 14.3 percent.

Concentration: the top ten hold 85.7 percent of proven crude oil; the other countries of the world share 14.3 percent.

That concentration is the main reason oil markets react so strongly to events in a small number of places. Five of the top six holders, Saudi Arabia, Iran, Iraq, the UAE and Kuwait, lie on the Persian Gulf, where tankers must pass the Strait of Hormuz to reach open sea. Only Saudi Arabia and the UAE have large bypass pipelines: the EIA puts the Saudi East-West pipeline at 7 million barrels per day, with 5 million available for exports, and the Abu Dhabi Crude Oil Pipeline at 1.8 million barrels per day. When the conflict involving Iran that began on 28 February 2026 closed the strait, the EIA reported that it lowered production across the region and limited the ability of OPEC+ to raise output, even though not a single barrel of proven reserves disappeared. Our coverage of the US and Israel war with Iran tracks that conflict, and weekly Brent, WTI and OPEC basket prices show how the market priced it.

The Middle East dominates the ranking on its own. Saudi Arabia, Iran, Iraq, the UAE, Kuwait and Qatar together report 862.5 billion barrels, 54.9 percent of the world total. For a regional view of production, exports and national oil companies, see the oil industry in the Middle East.

OPEC share of world reserves: 79.1 percent, or 71.4 percent after the UAE exit

At the end of 2025, OPEC had 12 member countries: Algeria, Congo, Equatorial Guinea, Gabon, Iran, Iraq, Kuwait, Libya, Nigeria, Saudi Arabia, the United Arab Emirates and Venezuela. Together they reported 1,243 billion barrels of proven crude oil, an increase of 2.19 billion barrels during 2025, according to the OPEC Secretariat. That is 79.1 percent of the world total, while non-OPEC countries held the other 329.0 billion barrels, or 20.9 percent.

After the exit: OPEC still holds 71.4 percent of proven crude oil, while the UAE alone accounts for 7.6 percent.

The exit matters more for production than for reserves. The EIA estimates that OPEC, including the UAE, produced 28.0 million barrels per day of crude oil in 2025, or 35 percent of world output, and that the share would have been 31 percent without the UAE. The UAE produced 3.4 million barrels per day in 2025 and had an estimated effective capacity of 4.2 million barrels per day, the third largest in OPEC after Saudi Arabia and Iraq. On reserves, the remaining group still controls seven of every ten proven barrels, and the three largest holders in the world, Venezuela, Saudi Arabia and Iran, are all still members.

OPEC share figures in older articles often look different because membership has changed several times. The ASB 2022 edition, for example, listed 13 members and put their combined reserves at 1,241.8 billion barrels for the end of 2021, 80.4 percent of the world total at the time. Comparing OPEC shares across years only works when the same group of countries is used.

Canada oil sands, Venezuela heavy oil and Russia: why the rankings differ

There is no single official world ranking of oil reserves. OPEC compiles its table from figures reported by national authorities. The EIA uses estimates from the Oil and Gas Journal survey. The Energy Institute Statistical Review of World Energy, which took over from the bp Statistical Review in 2023, used to publish a reserves table but has not updated it since the data for 2020, and its 2026 edition (the 75th) covers oil production, consumption, prices, refining and trade but no reserves. Eni, the Italian energy company, publishes its own World Energy Review with country reserves and reserve life. The chart compares OPEC and Eni for the ten countries where the numbers matter most.

Canada swings from 20th to 4th: counting oil sands adds about 196 billion barrels to Canada and lifts it above Iraq.

Canada: 5.1 billion barrels or 201.3 billion?

The largest gap is Canada. OPEC lists 5.08 billion barrels at the end of 2025 and notes that the figure excludes oil sands. Eni lists 201.3 billion barrels, up from 188.0 billion a year earlier, which would make Canada the fourth largest holder in the world, ahead of Iraq. The EIA, citing the Oil and Gas Journal, put Canada at 163 billion barrels as of January 2024 and said oil sands account for 97 percent of the total. Natural Resources Canada, in its Energy Fact Book for spring 2026, also states that 97 percent of Canadian proven oil reserves are in the oil sands.

The difference is a matter of definition, not geology. Oil sands bitumen is mined or produced with steam in place, and it is already commercial: Canada produced 5.4 million barrels per day of crude oil in 2025, of which 3.5 million barrels per day came from the oil sands, according to Natural Resources Canada. The Alberta Energy Regulator published a fully updated reserves assessment in September 2026 that puts total proved plus probable crude bitumen reserves at 187 billion barrels, effective 31 December 2023. Because that measure includes probable reserves, it is not directly comparable with the proven figures above.

Venezuela: the largest reserves, mostly extra heavy

Venezuela ranks first in OPEC, Eni and EIA data alike, with roughly 303 billion barrels. According to the EIA, most of those reserves are extra heavy crude oil in the Orinoco Belt. That oil is counted as proven by every major source, unlike Canadian bitumen in the OPEC table, which is why Venezuela leads every ranking while Canada moves between 20th and 4th place. Extra heavy crude is costly to produce and needs diluents or upgrading before it can be shipped and refined. Venezuela produced 742,000 barrels per day of crude oil in 2023, a 70 percent cumulative decline from 2013, according to the EIA, and its 2025 output was 0.94 million barrels per day in the EIA Short-Term Energy Outlook.

Russia, the UAE, Iraq and the United States

For Russia, OPEC has used 80.0 billion barrels in every year from 2017 to 2025, while Eni reports 107.8 billion. For the UAE, OPEC shows 120.0 billion barrels after a 7 billion barrel upgrade in 2025, while Eni still uses 113.0 billion. For Iraq the order is reversed: OPEC cut Iraq from 145.0 billion to 140.0 billion barrels, while Eni keeps 145.0 billion. For the United States, OPEC lists 41.9 billion barrels; the EIA official count of crude oil and lease condensate proved reserves was 45.951 billion barrels at the end of 2024, down 1 percent from 46.422 billion a year earlier.

Sources: OPEC ASB 2026 Table 3.1; Eni World Energy Review 2026 (oil reserves at 31 December 2025); EIA Country Analysis Briefs for Venezuela (February 2024) and Canada (May 2024), both citing the Oil and Gas Journal; EIA US Crude Oil and Natural Gas Proved Reserves, Year-End 2024. A dash means no comparable figure was published.

The totals differ for the same reasons. OPEC puts the world at 1,572.5 billion barrels for the end of 2025. Eni puts it at 1,802.5 billion barrels, about 230 billion more, almost all of it Canadian oil sands and the higher Russian estimate. The Oil and Gas Journal survey published in December 2024 counted 1,765.2 billion barrels. None of these is wrong; they answer slightly different questions, so the safest approach is to compare countries within one source, as this report does.

How many years would each country reserves last at 2025 output?

The reserves to production ratio divides proven reserves by one year of output. It shows how long reserves would last if production stayed at the current rate and no new reserves were added, which never happens in practice. On OPEC data, world crude oil reserves of 1,572.5 billion barrels and world crude output of 74.85 million barrels per day in 2025 give a ratio of 57.6 years (BusinessStats calculation). Using the EIA estimate of world crude output, 79.00 million barrels per day including lease condensate, the ratio is 54.5 years. Eni, using its larger reserves estimate, reports 49 years for the world and 100 years for OPEC in 2025.

Long and short: Iran and Libya have a century of reserves at their 2025 output, while the United States, the largest producer, has 6 years on Eni figures.

The ranking by reserve life looks very different from the ranking by size. Venezuela, at 806 years on Eni figures and 885 years on OPEC reserves and EIA output, is left out of the chart because it would flatten every other bar. Iran (123 years) and Libya (100 years) come next, both producers whose output has been held back by sanctions or conflict. At the other end, the United States has only 6 years of reserves on Eni figures and 8.4 years on the OPEC basis, even though it was the largest crude producer in the world in 2025 at 13.66 million barrels per day. US companies book reserves under strict financial reporting rules and replace them every year by drilling, so a short ratio is normal for a fast-growing shale producer and does not mean US output is about to run out. US consumption and production trends are covered in US fossil fuel consumption.

Reserves: OPEC ASB 2026, end-2025. Output: EIA Short-Term Energy Outlook, Table 3d (October 2026), 2025 crude oil production; UAE from EIA Today in Energy (23 June 2026). Years at 2025 output are BusinessStats calculations. Eni R/P from Eni World Energy Review 2026, which uses its own reserves estimates.

Reserve life also helps explain the 2026 market. Because the Gulf producers have the longest reserve lives and the lowest production costs, a disruption to their exports removes oil that cannot be replaced quickly from anywhere else. The effect on fuel bills is tracked in our gas prices report, and refining capacity, which turns this crude into fuel, is covered in global oil refinery industry statistics.

How the top five reserve holders changed between 2017 and 2025

Using the same OPEC series, the five largest holders at the end of 2025 can be traced back to 2017. Venezuela and Saudi Arabia have barely moved: Venezuela reported 302.8 billion barrels in 2017 and 303.7 billion in 2025, Saudi Arabia 266.3 billion and 267.2 billion. The changes came from Iran, the UAE and Iraq.

Reassessment, not discovery: Iran added 53.0 billion barrels in a single year, and the UAE 22.2 billion over eight years.

• Iran raised its reported reserves from 155.6 billion barrels at the end of 2018 to 208.6 billion at the end of 2019, an increase of 53.0 billion barrels in one year, and has reported the same figure since.
• The UAE went from 97.8 billion barrels in 2017 and 2018 to 105.0 billion in 2019, 107.0 billion in 2020, 111.0 billion in 2021, 113.0 billion in 2022 to 2024 and 120.0 billion in 2025.
• Iraq reported 147.2 billion barrels in 2017 and 145.0 billion from 2018 to 2021. OAPEC data show 140.0 billion for 2023 and 145.0 billion for 2024, and the OPEC 2026 edition shows 140.0 billion for 2025.
• The United States has moved the most among large holders in percentage terms: 39.2 billion barrels in 2017, 44.2 billion in 2019, 35.8 billion in 2020, a year of very low oil prices, 38.8 billion in 2021 and 41.9 billion in 2025.

The world total on the OPEC basis rose from 1,491.3 billion barrels at the end of 2017 to 1,572.5 billion at the end of 2025, a gain of 81.1 billion barrels or 5.4 percent. The single Iranian revision of 2019 accounts for 65 percent of that increase, and the UAE upgrades, 22.2 billion barrels in total, for another 27 percent. In other words, most of the growth in proven reserves over the period came from reassessments by a few governments rather than from new discoveries.

Plus 5.4 percent in eight years: world proven crude reserves rose by 81.1 billion barrels between the end of 2017 and the end of 2025.

Longer histories exist, but they mix sources. The bp and Energy Institute series, which starts in 1980, includes Canadian oil sands and differs from OPEC for several countries, so older figures from that series cannot be placed on the same chart without creating false jumps. This report therefore uses one consistent OPEC series from 2017.

The biggest reserve revisions in the 2026 edition

World reserves rose by 7.3 billion barrels in 2025, the net result of upward revisions in a handful of countries and cuts in others. The largest changes reported between the end of 2024 and the end of 2025 were:

Norway reported a cut of about 1.0 billion barrels, to 5.9 billion, and Venezuela an increase of 0.5 billion barrels, to 303.7 billion. The OPEC total for its 12 members rose by only 2.19 billion barrels, so most of the 7.3 billion barrel world increase came from outside the group, mainly China and Brazil.

These revisions are small next to the size of the top holders, but they show which numbers are actively managed. The United States and China changed their reported figures in every year from 2017 to 2021 in the OPEC tables, while most large OPEC producers revise rarely and in big steps. For the gas side of the same picture, see our page on Russian natural gas, and for the pipelines and tankers that move crude from these fields, the global oil and gas transportation industry.

What large reserves do and do not tell you

A large reserve figure is a measure of potential, not of supply. Venezuela holds about seven times the reserves of the United States on OPEC figures, yet in 2025 it produced 0.94 million barrels per day of crude against 13.66 million in the United States. Iran holds the third largest reserves but produced 3.38 million barrels per day, about a third of Saudi output. Production depends on investment, sanctions, infrastructure, the quality of the crude and the cost of extracting it.

Reserves also interact with the energy transition. Burning proven reserves releases carbon dioxide, which is why climate researchers compare reserves with the remaining carbon budget; emissions data are in our global greenhouse gas emissions report. Countries with very long reserve lives and low costs, mostly in the Gulf, are best placed to keep producing as demand growth slows, while high cost producers face more risk that part of their reserves will never be extracted. A broader view of energy markets is collected on our energy and environment statistics hub.

Methodology and data notes

Country reserves, the world total and the OPEC total come from Table 3.1 of the OPEC Annual Statistical Bulletin 2026, which reports proven crude oil reserves in million barrels at 31 December 2025. OPEC announced the world and OPEC totals (1,572 billion and 1,243 billion barrels) when it launched the bulletin. Shares of the world total, top ten and top twenty sums, the OPEC share without the UAE and all years at 2025 output figures are BusinessStats calculations. Figures in the text are rounded to one decimal place; the top 20 table shows OPEC values to three decimals where OPEC reports them.

History for 2017 to 2021 is from Table 3.1 of the OPEC ASB 2022 edition, and the world total for the end of 2024 is from the OPEC ASB 2025 launch statement (1,567 billion barrels); OPEC revised 2024 slightly in the 2026 edition. Iraq and UAE values for 2022 to 2024 are from the OAPEC Annual Statistical Report 2025. Production for 2025 is from Table 3d of the EIA Short-Term Energy Outlook released in October 2026; that table no longer lists the UAE, so the UAE figure comes from the EIA Today in Energy article of 23 June 2026. Eni figures are from the oil chapter of the Eni World Energy Review 2026. The Energy Institute Statistical Review was checked and does not contain current reserves data.

The previous version of this page mixed reserve figures from different sources and years, cited secondary websites and used rounded estimates for several countries. It has been rebuilt on one consistent dataset, with every alternative figure labelled by source and date.

Oil reserves by country in eight numbers

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