The five major contributors to the United Nations regular annual budget for the 2025–2027 assessment period are the United States, China, Japan, Germany, and the United Kingdom. Member states' mandatory (assessed) contributions are calculated based on their capacity to pay, factoring in gross national income (GNI) and population.

The five major contributors to the United Nations regular annual budget for the 2025–2027 assessment period are the United States, China, Japan, Germany, and the United Kingdom. Member states' mandatory (assessed) contributions are calculated based on their capacity to pay, factoring in gross national income (GNI) and population.

The assessed contributions for the top 5 member states are as follows:

- United States: 22.00%

- China: 20.004%

- Japan: ~8.03% to 8.56% (historically the third-largest)

- Germany: ~6.09%

- United Kingdom: ~4.0% to 4.5%

Together, the financial assessments for the United States and China alone account for about 42% of the UN's entire regular budget.

If you'd like to explore how UN funding is allocated, I can:

- Detail how the UN determines individual scales of assessment.

- Compare these figures against voluntary contributions to specific UN agencies.

- Provide historical context on how these percentages have evolved.

Let me know if you would like to narrow down the list or explore a specific area of UN financing.