The US government's Bureau of Economic Analysis as of Q3 2023 estimates $10.0 Trillion in annual total government expenditure and $27.6 trillion annual total GDP which is 36.2%.

The OECD for 2021 shows general US government spending at 44.9% of GDP, or $31,538 per capita. BEA's percentage is smaller because it just includes government spending. OECD's total is larger because it also includes fees, e.g. tuition payments at public colleges.

The US Federal reserve also has trillions in corporate bond and other purchases.

China has lower direct government spending but this increases when the State owned enterprises are included. China's state owned enterprises are about 20% of the economy. The US government supports 45% of the healthcare industry revenues. There is also large government support and involvement with military companies and several other industries.