What is Bitcoin halving?

The scheduled event, every 210,000 blocks or roughly every four years, that cuts the reward paid to Bitcoin miners in half.

The April 2024 halving cut the reward from 6.25 BTC to 3.125 BTC per block, and the next is expected around April 2028 (source: CoinGecko halving countdown). Halvings slow the issuance of new coins until the 21 million cap is reached.

It is scheduled by block count rather than by date, so nobody has to agree to it and nobody can postpone it. The date drifts because block times vary, which is why countdowns give an estimate rather than a fixed day.

How it works

Bitcoin Core's consensus code computes the subsidy by starting at 50 coins and halving it once per subsidy halving interval, which is 210,000 blocks, forcing the reward to zero once 64 halvings have occurred (source: Bitcoin Core, GetBlockSubsidy in validation.cpp).

At a ten-minute target block time, 210,000 blocks is about four years. The actual interval is shorter when hash rate grows faster than the difficulty adjustment can compensate, which is why halvings have arrived slightly early rather than late.

What halves is the block subsidy, the newly created coins. Transaction fees in the same block are unaffected, so total miner revenue falls by less than half whenever fees are a meaningful share.

The economic consequence for miners is immediate: the same electricity and hardware now produce half the new coins. Operations with high costs shut off, hash rate falls, and the difficulty adjustment lowers the target so blocks return to a ten-minute pace.

The geometric series of halvings sums to just under 21 million coins, which is where the supply cap comes from. There is no separate rule enforcing it.

Example

Illustrative arithmetic on issuance. At 3.125 BTC per block and about 144 blocks a day, new supply is roughly 450 BTC per day. Before the April 2024 halving, at 6.25 BTC per block, it was roughly 900 BTC per day. Over a year that is a fall from about 328,500 to about 164,250 new coins, holding block pace constant. Block pace varies, so these are approximations.

Illustrative; daily figures assume exactly 144 blocks, which varies in practice.

Why it matters when you buy

Halvings change the rate of new supply, which is one input into price among many, and they are known years ahead. What they change for you directly is mining economics and, through that, the fee market: as the subsidy shrinks, transaction fees carry more of the security budget, which affects what withdrawals cost. Compare withdrawal costs at the fee comparison and see the Bitcoin asset page.

Related terms

• block subsidy — the part of the reward that halves
• block reward — subsidy plus fees together
• mining — the activity the subsidy pays for
• difficulty adjustment — what restores block pace afterwards
• hash rate — the measure that falls when miners switch off
• emission schedule — the general term for issuance over time

Questions

When exactly is the next halving?

It is set by block height, not by date, so countdowns estimate from recent block pace. The estimate moves by days as hash rate changes.

Does the halving make Bitcoin more valuable?

It reduces the rate of new supply, which is one factor among many. Price depends on demand as well, and RampAtlas does not make price predictions.

What happens when the subsidy reaches zero?

Miners are paid entirely from transaction fees. The code forces the subsidy to zero after 64 halvings, which on the current schedule is well over a century away.