21 million and no more

New bitcoin is created only as a reward to miners, and the amount follows a fixed schedule. It started at 50 per block. Every 210,000 blocks, about four years, the reward is cut in half. This is the halving.

Because the reward keeps halving, the total approaches but never exceeds 21 million. The last fraction will be issued around the year 2140.

Smallest unit

One bitcoin divides into 100 million satoshis ("sats"). You never need to own a whole bitcoin to take part.

One thing to remember

The supply schedule is public and known in advance. You can see it on the halving countdown and the sats converter.