How much does the world spend on the military each year?

How to get close to this number

Take a share of world output. The explanation gives it as about two and a half percent of global GDP, and world output is on the order of a hundred trillion dollars. That percentage of that total gives a figure in the low trillions, which is where the answer sits.

The share is the telling detail. For years military budgets grew roughly in step with the world economy, so the fraction of output spent on arms barely moved; the highest share since 2009 means spending is now outpacing growth. That is why people anchored on an older headline guess low: the total has been rising faster than the economy that pays for it, with Europe rearming fastest.

The concentration is the structural fact: one country spends roughly a third of the total, more than the next seven combined. Global military spending is not a distributed phenomenon but a single national budget plus everyone else, which is why changes in one country’s defence policy move the world figure measurably — in either direction.