Bitcoin Basics · Episode 5 · 90 seconds, narrated

The 21 Million Rule

A short cartoon about why bitcoin's supply has a hard cap: new blocks, the halving, and how the total creeps toward 21 million. Turn your sound on and press play, or jump to a chapter.

0:00 / 1:34

Numbers in this episode

~10 min: Average time between blocks. The network adjusts mining difficulty every 2,016 blocks to hold this pace.
210,000: Blocks between halvings, which works out to about four years.
50 → 3.125: Block reward in 2009 versus after the April 2024 halving. The next cut, to 1.5625 BTC, is expected around 2028.
≈ 20.1M: Bitcoin mined by October 2026, estimated from the issuance schedule. That is about 96% of the cap.
≈ 2140: When the last fraction of a bitcoin is expected to be mined.

Script

Read the narration

For education only; not investment advice. Halving years are approximate because block times vary. Narration uses a synthetic voice (Kokoro text-to-speech). Part of Bitcoin Basics from The Steady Block: @TheSteadyBlock on YouTube and X, TheSteadyBlock.com.