Solo mining odds: chance to find a Bitcoin block
With a Bitaxe Gamma (601) (1.2 TH/s) the chance of finding a block solo at today's difficulty is 0.0063% per year (1 in 15,955). It is a lottery, not income.
Difficulty: 140.58 T · Network hashrate: 1039 EH/s, mempool.space (3-day avg) · Data: 22 Oct 2026, 21:46 London · Block subsidy: 3.125 BTC
Calculator
| 1 hour | <0.0001% | 1 in 140 million |
| 1 day | <0.0001% | 1 in 5.82 million |
| 1 week | 0.00012% | 1 in 831,924 |
| 1 month (30 d) | 0.00052% | 1 in 194,116 |
| 1 year | 0.0063% | 1 in 15,955 |
| 10 years | 0.063% | 1 in 1,596 |
Poisson model at the current difficulty. Difficulty tends to rise, so real odds are usually lower. This is a lottery, not income.
Source: mempool.space (3-day avg) · as of 22 Oct 2026, 21:46 London · network difficulty from the same snapshot; odds computed by 21btc with a Poisson model, not a forecast
How the odds work
Every hash is an independent attempt. Expected blocks per day = your hashrate × 86,400 ÷ (difficulty × 2³²). The probability of at least one block over t days = 1 − e^(−λt) (a Poisson model; the same as 1 − (1 − p)^n with p = hashrate share and n ≈ 144 blocks a day). Time already spent does not raise the odds.
Typical devices
| Device | TH/s | Chance / year | Expected years |
|---|---|---|---|
| NerdMiner v2 | ~50–80 KH/s | <0.0001% | 245 billion |
| Bitaxe Ultra (204/205) (approximate spec) | 0.5 | 0.0026% | 38,291 |
| Bitaxe Supra (401) (approximate spec) | 0.65 | 0.0034% | 29,455 |
| Bitaxe Gamma (601) | 1.2 | 0.0063% | 15,955 |
| Bitaxe GT (Gamma Turbo) (approximate spec) | 2.2 | 0.011% | 8,703 |
| NerdQAxe++ | 4.8 | 0.025% | 3,989 |
| NerdOctaxe Gamma (approximate spec) | 9.7 | 0.051% | 1,974 |
| Avalon Nano 3S | 6 | 0.031% | 3,191 |
| Avalon Nano 3 | 4 | 0.021% | 4,786 |
| Braiins Mini Miner BMM 101 | 1 | 0.0052% | 19,146 |
| FutureBit Apollo II | 6 | 0.031% | 3,191 |
Hashrates are manufacturer figures from our catalogue, not measurements. The calculation is ours; no competitor figures are copied. Solo miners in the shop →
Expected value vs lottery
A block pays the 3.125 BTC subsidy plus fees (see Network). Expected value is the same solo and in a pool before pool fees, but solo has high variance: you can get nothing for years and the whole reward once.
Pool vs solo
A pool shares rewards by contribution and charges a fee; solo keeps everything for you, but rarely. Pool comparison → · solo-ckpool · Mining at home →
Mining income calculator → · Hashrate → · ASICs in the shop → · Mining (wiki) →
FAQ
- What is the chance of mining a Bitcoin block solo?
- It equals your share of the network hashrate. For a Bitaxe Gamma (601) (1.2 TH/s) at the current difficulty that is 0.0063% per year, 1 in 15,955. It is a lottery.
- Is solo mining profitable?
- Expected revenue is the same as in a pool (hashrate share × reward), but it arrives as a rare large payout while you pay for power all the time. For small miners it is closer to a lottery and a hobby than income.
- How long to find a block with a Bitaxe?
- The model gives an expected time of about 15,955 years for a Bitaxe Gamma (601) at today's difficulty. That is an average; the actual time can be anything.
- Does running longer increase my odds per block?
- No: each block is an independent attempt, so time already spent does not raise the odds. The total probability over a period does grow with its length.
- Pool vs solo mining?
- A pool smooths payouts for a fee; solo gives a rare chance at the whole block reward. See the pool comparison.
- Has anyone found a block solo with small hardware?
- We do not quote a count because we have not verified one against a primary source.
Methodology
Network difficulty and hashrate: mempool.space (with fallbacks, as on the Network page). Device hashrates: our solo-miner catalogue. Not investment advice.