Supply & Issuance
Bitcoin's Maximum Supply
Why Bitcoin's hard cap is exactly 20,999,999.9769 ₿ - not 21 million.
Bitcoin's subsidy schedule halves every 210,000 blocks, starting at 50 ₿. Because Bitcoin Core uses integer division (floor) to compute each epoch's subsidy in satoshis, rounding losses accumulate across 33 epochs and the total falls 0.0231 ₿ short of 21 million. This is not a bug - it is a direct consequence of how integer arithmetic works, and every full node enforces the same result independently.
The last non-zero subsidy epoch is Epoch 32, paying 1 sat per block. After that, floor(1 / 2) = 0, and no further coins will ever be issued. The last satoshi will be mined around the year 2139, in block 6,929,999.
The total supply in ₿ is the sum over all 33 epochs of the per-block subsidy (in satoshis, floored by integer division) multiplied by 210,000 blocks per epoch, divided by 108 to convert to ₿:
The floor function ⌊⌋ is key. From epoch 10 onward, integer division starts producing rounding losses - for example, floor(50 × 108 / 210) = 4,882,812 sat instead of 4,882,812.5 sat. These sub-satoshi losses accumulate across the remaining epochs, totalling 2,310,000 sat (0.0231 ₿) that will never exist.
Source: Bitcoin Wiki - Controlled supply
| Epoch | Subsidy / block | Sat / block | Blocks | Total issued | % of max | Cumulative |
|---|---|---|---|---|---|---|
| #0 | 50.00000000 ₿ | 5,000,000,000 | 210,000 | 10500000.0000 ₿ | 50.00000006% | 10500000.0000 ₿ |
| #1 | 25.00000000 ₿ | 2,500,000,000 | 210,000 | 5250000.0000 ₿ | 25.00000003% | 15750000.0000 ₿ |
| #2 | 12.50000000 ₿ | 1,250,000,000 | 210,000 | 2625000.0000 ₿ | 12.50000001% | 18375000.0000 ₿ |
| #3 | 6.25000000 ₿ | 625,000,000 | 210,000 | 1312500.0000 ₿ | 6.25000001% | 19687500.0000 ₿ |
| #4 | 3.12500000 ₿ | 312,500,000 | 210,000 | 656250.0000 ₿ | 3.12500000% | 20343750.0000 ₿ |
| #5 | 1.56250000 ₿ | 156,250,000 | 210,000 | 328125.0000 ₿ | 1.56250000% | 20671875.0000 ₿ |
| #6 | 0.78125000 ₿ | 78,125,000 | 210,000 | 164062.5000 ₿ | 0.78125000% | 20835937.5000 ₿ |
| #7 | 0.39062500 ₿ | 39,062,500 | 210,000 | 82031.2500 ₿ | 0.39062500% | 20917968.7500 ₿ |
| #8 | 0.19531250 ₿ | 19,531,250 | 210,000 | 41015.6250 ₿ | 0.19531250% | 20958984.3750 ₿ |
| #9 | 0.09765625 ₿ | 9,765,625 | 210,000 | 20507.8125 ₿ | 0.09765625% | 20979492.1875 ₿ |
| #10 | 0.04882812 ₿ | 4,882,812 | 210,000 | 10253.9052 ₿ | 0.04882812% | 20989746.0927 ₿ |
| #11 | 0.02441406 ₿ | 2,441,406 | 210,000 | 5126.9526 ₿ | 0.02441406% | 20994873.0453 ₿ |
| #12 | 0.01220703 ₿ | 1,220,703 | 210,000 | 2563.4763 ₿ | 0.01220703% | 20997436.5216 ₿ |
| #13 | 0.00610351 ₿ | 610,351 | 210,000 | 1281.7371 ₿ | 0.00610351% | 20998718.2587 ₿ |
| #14 | 0.00305175 ₿ | 305,175 | 210,000 | 640.8675 ₿ | 0.00305175% | 20999359.1262 ₿ |
| #15 | 0.00152587 ₿ | 152,587 | 210,000 | 320.4327 ₿ | 0.00152587% | 20999679.5589 ₿ |
| #16 | 0.00076293 ₿ | 76,293 | 210,000 | 160.2153 ₿ | 0.00076293% | 20999839.7742 ₿ |
| #17 | 0.00038146 ₿ | 38,146 | 210,000 | 80.1066 ₿ | 0.00038146% | 20999919.8808 ₿ |
| #18 | 0.00019073 ₿ | 19,073 | 210,000 | 40.0533 ₿ | 0.00019073% | 20999959.9341 ₿ |
| #19 | 0.00009536 ₿ | 9,536 | 210,000 | 20.0256 ₿ | 0.00009536% | 20999979.9597 ₿ |
| #20 | 0.00004768 ₿ | 4,768 | 210,000 | 10.0128 ₿ | 0.00004768% | 20999989.9725 ₿ |
| #21 | 0.00002384 ₿ | 2,384 | 210,000 | 5.0064 ₿ | 0.00002384% | 20999994.9789 ₿ |
| #22 | 0.00001192 ₿ | 1,192 | 210,000 | 2.5032 ₿ | 0.00001192% | 20999997.4821 ₿ |
| #23 | 0.00000596 ₿ | 596 | 210,000 | 1.2516 ₿ | 0.00000596% | 20999998.7337 ₿ |
| #24 | 0.00000298 ₿ | 298 | 210,000 | 0.6258 ₿ | 0.00000298% | 20999999.3595 ₿ |
| #25 | 0.00000149 ₿ | 149 | 210,000 | 0.3129 ₿ | 0.00000149% | 20999999.6724 ₿ |
| #26 | 0.00000074 ₿ | 74 | 210,000 | 0.1554 ₿ | 0.00000074% | 20999999.8278 ₿ |
| #27 | 0.00000037 ₿ | 37 | 210,000 | 0.0777 ₿ | 0.00000037% | 20999999.9055 ₿ |
| #28 | 0.00000018 ₿ | 18 | 210,000 | 0.0378 ₿ | 0.00000018% | 20999999.9433 ₿ |
| #29 | 0.00000009 ₿ | 9 | 210,000 | 0.0189 ₿ | 0.00000009% | 20999999.9622 ₿ |
| #30 | 0.00000004 ₿ | 4 | 210,000 | 0.0084 ₿ | 0.00000004% | 20999999.9706 ₿ |
| #31 | 0.00000002 ₿ | 2 | 210,000 | 0.0042 ₿ | 0.00000002% | 20999999.9748 ₿ |
| #32 | 0.00000001 ₿ | 1 | 210,000 | 0.0021 ₿ | 0.00000001% | 20999999.9769 ₿ |
| Total (33 epochs) | 20,999,999.9769 ₿ | 100% | 20,999,999.9769 ₿ | |||
The theoretical maximum of 20,999,999.9769 ₿ is the sum of all subsidies across every epoch until the last satoshi is mined around 2139. The gross issued supply at the current block height is lower - it only counts subsidies already paid. Additionally, – in known unclaimed subsidies permanently reduce the effective hard cap to –.
- Supply - live issued supply, UTXO set total, and issuance milestones.
- Subsidy Epochs - current epoch progress, halving countdown, and per-era timing.
- Provably Unspendable Bitcoin - Bitcoin whose loss is verifiable on-chain: genesis block, unclaimed subsidies, and OP_RETURN burns.
- Unclaimed Block Subsidies - blocks where the miner left bitcoin on the table permanently.