Halving countdown

What the halving is, how the expected date is worked out and why it moves.

Every 210,000 blocks the bitcoin block reward is cut in half. That is the halving, roughly every four years. The halving countdown shows how long is left.

1. CountdownDays, hours, minutes and seconds to the expected halving time. Ticks every second.
2. Progress barHow much of the current 210,000-block epoch has passed.
3. Blocks leftHow many blocks miners still have to find.
4. Estimated dateWhen the halving block will most likely be found.
5. Current blockThe height of the latest block.
6. Halving blockThe block number where the reward drops.
7. Block rewardWhat a miner gets per block now and after the halving.

How it is calculated

epoch = ⌊current block ÷ 210,000⌋
halving block = (epoch + 1) × 210,000
blocks left = halving block − current block
expected time = now + blocks left × average block time
reward = 50 ÷ 2^epoch BTC

The average block time comes from mempool.space for the current difficulty period. The protocol aims for one block every 10 minutes, but blocks come faster or slower with the hashrate.

So while the halving is far away, the date can move by several days. The halving block number never changes.