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LESSONS

The supply schedule

New bitcoin is issued on a declining schedule anyone can compute. Roughly 95% exists already; the last fractions arrive around 2140.

6 MIN READ
The 21 million cap and the final issuance around 2140.
LEVEL · Intermediate
IN THIS LESSON · 1 OF 6
BY THE END YOU WILL BE ABLE TO ANSWER
  • Why is the final supply slightly under 21 million?
  • What enforces the subsidy?
  • Era 6 (blocks 1,050,000 to 1,259,999) pays 1.5625 BTC per block. How many BTC are issued in that era?

Then prove it: a 2-question quiz · a challenge. The lesson marks itself complete at 100%.

Bitcoin's rules cap the total at 21 million. New coins are created only as the block subsidy paid to miners, and that subsidy follows a schedule fixed in the code since 2009.

The arithmetic

Each era lasts 210,000 blocks. The subsidy starts at 50 BTC and halves each era:

Era Blocks Subsidy Issued in era Cumulative
1 0–209,999 50 10,500,000 10,500,000
2 210,000–419,999 25 5,250,000 15,750,000
3 420,000–629,999 12.5 2,625,000 18,375,000
4 630,000–839,999 6.25 1,312,500 19,687,500
5 840,000–1,049,999 3.125 656,250 20,343,750

The series sums toward 21 million and never reaches it. Because the subsidy is an integer number of satoshis and halving rounds down, the final total is 20,999,999.9769 BTC. The last satoshi is issued around the year 2140, at the 33rd halving.

Where we are

As of 2026, over 19.9 million bitcoin have been issued, about 95% of the total. Annual issuance is below 1% of supply, lower than gold's. Check the live figures on the Bitcoin Charts dashboard.

Why anyone can trust it

The schedule is not a promise. Every node checks that each block's coinbase pays at most the subsidy for that height plus fees. A block paying more is invalid everywhere.

MINI CHALLENGESupply after era 6

Era 6 (blocks 1,050,000 to 1,259,999) pays 1.5625 BTC per block. How many BTC are issued in that era?

BTC
CHECK YOURSELF
1/2 Why is the final supply slightly under 21 million?
2/2 What enforces the subsidy?
pick an answer for each question

SOURCES

  1. Bitcoin: A Peer-to-Peer Electronic Cash System (Satoshi Nakamoto, 2008)
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