Bitcoin security budget · the schedule

When does Bitcoin's block subsidy end?

The subsidy halves roughly every four years and reaches zero around 2140. But the date that matters is much sooner: at the ~April 2028 halving it drops from 3.125 to 1.5625 BTC per block, and the security budget drops from 0.82% of market cap a year to 0.41%.

The schedule, and what it does to the budget

EventSubsidySecurity budget
Today (2026-09-07)3.125 BTC0.82%
~April 20281.5625 BTC0.41%
~20320.78125 BTC0.21%
~20360.390625 BTC0.11%
~21400fees only

Why 2140 is the wrong date to watch

2140 is when the subsidy reaches zero, and it is far enough away to feel theoretical. The problem arrives long before that, because each halving removes half of what remains. Two halvings from now, in ~2032, the budget is 0.21% of market cap a year, which is already below every published estimate of what is adequate. The question is not what happens in 2140; it is what replaces the subsidy over the next two halvings.

What would have to fill it

Fees are the only in-protocol candidate. They are 0.64% of miner revenue over the last 30 days and would need to reach about 18% permanently, roughly 29× today’s level, to close the gap to 1%. Bitcoin’s longest run above 20% of miner revenue is 40 days. See whether fees can replace the subsidy.

Sources

Figures as of 2026-09-07 · generated 2026-09-08 from the same data file that feeds the FAQ’s sizing section. How these figures are computed · about & corrections. Machine-readable: data.json, history.csv. Dated permalink: /security-budget/2026-09-07/.