What are the largest air forces in the world by budget? Short answer: no one really knows. No matter the criteria used, it is clear that the United States Air Force has the world's largest such budget, but beyond that, it gets murky. Many countries, like the UK, China, and Russia, do not provide breakdowns in their military budgets for how much is spent specifically on the air force. Other big issues include converting currencies, and the different expenses are included or excluded between air force budgets. For example, the US Air Force budget includes nuclear expenses.

One problem particularly acute with China is that no one really even knows its military expenditure, with official numbers widely believed to be greatly understated. Another issue, particularly acute with the US, is whether the term "air force" can also be extended to the aviation arms of the US Navy, Marines, and Army. If so, then these immediately score among the most financed "air forces" in the world.

1 The USAF Clearly In The Lead

Understanding the military budget of the United States Air Force is comparatively easy. This is thanks to Washington publicly releasing very generous line-by-line breakdowns of its military expenditure (something classified by many governments), including budget allocations by service branch. Additionally, as the base currency is the US dollar, there is no need to convert it with all the messiness that that brings.

The United States Air Force has a total budget of around $188 billion, making it by far and away the largest in the world. But then there's another question. What is the US Air Force? The definition could be the Department of the Air Force, which also includes the US Space Force. After all, the space sector remains part of the regular air force in many countries, like France. If the Space Force is added, then the USAF budget grows by around $30 billion to almost $218 billion.

Conversely, one might want to trim the USAF budget to bring it more in line with the budgets of other countries' air forces. If one were to think of the Air Force as a service branch with airplanes and spending all its money on those airplanes, one would be wrong. Somewhere around 10% of the USAF budget goes toward upkeeping the US nuclear deterrent, and it's the USAF that has to pay for the next-generation Sentinel ICBM. Meanwhile, a country like Australia will spend much more of its allocated budget directly on its aircraft and related operations.

2 The United States' Other Three Air Forces

One can argue that the US has five air forces: the USAF, the Navy, the Marines, the Army, and the Coast Guard, to a much smaller degree. Aviation is one of the largest expenditures for the Navy. Just as the US Air Force and Space Force are in the Department of the Air Force, the Navy and Marines are in the Department of the Navy. The Department of the Navy has a budget of around $257 billion, which includes around $204 billion for the Navy and $53 billion for the Marines. The Navy spends around 25–30% of its budget on aviation, while the Marines spend around 35–40%.

Overall, it's reasonable to estimate that around $65–70 billion is spent on aviation by the Department of the Navy. This would potentially make it the second-most funded "air force" in the world, although it might be outspent by the Chinese PLAAF (more on that later). At any rate, if this were a standalone budget, it would be enough to edge into the world's top ten military budgets.

After the establishment of the US Air Force in 1947, the US Army lost almost all of its aviation. It rebuilt its aviation arm focused on rotary-wing aircraft, and today it spends a comparable amount of money on aviation procurement as it does on vehicle procurement. Of the Army's $180 billion budget, around 10-15% is spent on aviation, amounting to around $20 billion, which is likely more than the UK RAF and French Air Force.

3 Tricky Issue Of China

All numbers for China are problematic. The official Chinese military budget for 2025, as provided by the 2025 National People's Congress announcement, is $246 billion equivalent. But this is widely believed to be under-reported, and SIPRI estimates the actual number is closer to $318 billion. Other estimates suggest China's budget is over $400 billion and as much as $470 billion.

Another major issue is that China does not break down its budget allocation like the United States. Additionally, China has a large and rapidly growing naval aviation arm. It's reasonable to assume that the People's Liberation Army Air Force (PLAAF) consumes around 20–25% of the total budget, especially as China has placed more emphasis on its air force over the last few years.

This would suggest the PLAAF has a budget of around $50 billion to $62 billion based on the official $246 billion budget. But that could be around $80 billion if SIPRI's estimate is accurate, or even close to $100 billion, should SIPRI be significantly undercounting the budget. Regardless, it's clear that it's the second-largest budget with financing in nominal USD terms, most comparable to the US Navy's aviation budget.

4 The Russian Air Force

The Russian Air Force has fallen on hard times. Not only has the massive force failed to secure air superiority over Ukraine, but it has also suffered significant attritional losses, and around half of its tactical aircraft are now dated (e.g., MiG-29s, Su-27s, Su-24s, Su-25s). Making matters worse, the country has fallen technologically behind China, and it's now reasonable to assess that China's most recent Flanker variants are more capable than Russia's most recent Flanker variants.

Still, excluding the US Navy, the Russian Air Force likely remains the third-largest budget. The Russian military budget is estimated to be between $100 billion and $175 billion; unfortunately, there is a lot of uncertainty, and official numbers may not be representative of true spending. Making matters worse is the volatility of the Russian Ruble, which means Russia's budget in USD terms can swing wildly depending on when the conversion is done.

If a somewhat middle-of-the-road figure of $150 billion is taken, and an estimate of 20–30% of that budget is allocated to the Air Force, then its budget would be in the ballpark of $30 to 45 billion. These numbers should be taken with a pinch of salt due to uncertainty. The current conflict has likely seen Russia prioritize its army most of all, while deprioritizing the navy, as well as expensive next-generation air force fighter jet programs of no use to the current situation.

5 Other Leading Air Force Budgets

After the US, China, and Russia, it's somewhat difficult to estimate which country has the next largest air force budget. It becomes something of a first among equals, and currency movements and what expenses are included or excluded (e.g., nuclear) can make a big difference. Saudi Arabia could have the fourth-largest air force budget, as it has a total budget of $78 billion and is thought to spend a substantial 25% of that on the air force.

This would give Saudi Arabia an air force budget of around $20 billion, similar to the US Army's aviation budget. India has a total budget of around $79 billion, but a greater share of that goes to its navy and army. The Indian Air Force might have a budget of $13–14 billion (17%). That said, purchasing Rafales and other fighter jets may have pushed its budget up more, and the true Indian budget could be closer to $86 billion.

According to SIPRI estimates, the RAF has a budget of $12–18 billion, the French Air & Space has $9–14 billion, and the German Luftwaffe has $8–16 billion. Other significant budgets include Japan ($10-14 billion) and South Korea ($9–13 billion). Italy, Poland, Australia, Israel, and others have significant budgets.

6 Budgets, Airframe Numbers, & Capabilities Are Different Things

It should be stressed that the correlations between air force budgets, the number of aircraft in service, and the air force's capabilities are tenuous. The Pakistani Air Force has a much smaller budget compared with the RAF. However, it is much larger as measured by the number of fighter jet airframes in service.

On paper, North Korea has one of the world's largest air forces by number of jets, but they are almost all horribly obsolete jets with some dating from soon after the Korean War. They have no chance of having a meaningful impact in any conflict on the peninsula. Separately, the USAF has a large presence in South Korea, and the USAF spends a large amount of money maintaining its many airbases around the world.

Air forces are built for different things. Only the US Air Force is built for true power projection around the world. This is seen in that the USAF has around 75% of the world's tankers. Tankers are vital to power projection. Most other air forces are mostly built for defense, and that is partly why the Russian Air Force proved incapable of securing air superiority despite a large budget and large numbers of aircraft.