Halving halves Block Subsidy every 210,000 mainnet blocks. It changes neither holders’ balances nor satoshis per BTC; transaction fees are not halved.
Blocks 630,000–839,999 allow 6.25 BTC subsidy; 840,000–1,049,999 allow 3.125 BTC. The validated block’s height matters, not when a template was assembled or the miner transmitted it. [Bitcoin Core v29.0: GetBlockSubsidy]
210,000 ten-minute intervals span about four years. Real discoveries are random and hashrate changes, so calendar countdowns are estimates. The next boundary height is exact; its future calendar instant is not. [Bitcoin Core v29.0: GetBlockSubsidy]
At unchanged price and other conditions, the subsidy share of block income falls. Total revenue includes variable fees; net results also depend on electricity, hashrate, difficulty and equipment cost. Retarget is separate and does not automatically restore profit. [Bitcoin Core v29.0: GetBlockSubsidy]
Halving is a known issuance rule, not a price-rise guarantee. Past cycles alone determine neither future demand nor market reaction timing. Verify heights and subsidy on adjacent boundary blocks; price claims require different evidence. [Bitcoin Core v29.0: GetBlockSubsidy]
The subsidy eras
The subsidy began at 50 BTC per block, then fell to 25, 12.5, 6.25 and 3.125 BTC at successive 210,000-block boundaries. The next boundary is block 1,050,000; the calendar date is only an estimate.
For the clearest picture, read this entry together with Block Subsidy, 21 Million, Mining, Difficulty adjustment. The reverse links also lead from Block Subsidy, 21 Million, Satoshi, Stock-to-flow ratio.
01Who triggers a Bitcoin halving?+
Nobody sends a command. Every validating node calculates the allowed subsidy from block height and rejects a block that claims too much.
02Does a halving guarantee the price will rise?+
No. It reduces new issuance at a known height, but price also reflects demand, expectations, liquidity, miner behavior and broader market conditions.