As of publication, Bitcoin's network hashrate sits above 900 exahashes per second, that's computing power equivalent to 900 million TH/s contributed by ASICs spread across mining facilities worldwide. Against that backdrop, asking about Bitcoin solo mining odds can feel almost absurd: how does one machine in a garage compete with that? The honest answer is that it competes exactly the way any low-probability event does, through arithmetic, not hope. This guide treats Bitcoin solo mining odds as what they really are: a straightforward calculation shaped by network scale, difficulty adjustment periods, and the specific hardware you point at the chain. By the end, you will be able to run your own numbers with OwnBlock's free calculator and decide, with real figures in hand, whether solo mining fits your setup.

The Scale Problem: What 900+ EH/s Actually Looks Like Next to Your Rig

Start with the raw comparison, because it lets you see the scale of the problem immediately. 900 EH/s is 900,000,000 TH/s. An Antminer S21 running at roughly 200 TH/s controls a share of the network equal to 200 divided by 900,000,000, about 0.000000222, or 2.22 × 10⁻⁷. That fraction is a good approximation of your probability of finding the next block against the rest of the network. Multiply it by the roughly 144 blocks Bitcoin produces per day network-wide, and you get an expected 0.000032 blocks per day for that one machine, meaning, on average, you would need around 31,000 days, or roughly 86 years, of continuous mining to find one block by yourself. That is the scale problem in plain numbers: not impossible, but the network is large enough that a single rig cannot out-brute-force it.

Difficulty Adjustment Periods: Why Your Odds Shift With Every Retarget

Bitcoin recalculates mining difficulty every 2,016 blocks, roughly every two weeks, to keep block times close to ten minutes as total network hashrate rises or falls. When additional hashrate joins the network in a sustained way, the next retarget tends to push difficulty up; when power leaves the network, the opposite can happen. That is why the 900+ EH/s figure is a snapshot, not a constant to project years into the future: any long-term estimate should be recalculated periodically against the prevailing difficulty rather than treating today's hashrate as fixed.

From a Bitaxe to an Antminer S21: What Real Hardware Actually Buys You

The hardware you run does not make a marginal difference, it changes the entire time horizon you are working with. Here is what the maths looks like for machines people actually run:

  • A Bitaxe at ~1.2 TH/s: against a ~900 EH/s network, expected time comes out around 14,000 years. That makes it an extremely low-probability form of solo mining, closer to an educational experiment than an income strategy, and it draws very little power next to an industrial ASIC.
  • An Antminer S19 at ~110 TH/s: expected time drops to roughly 156 years, still generational, but about 90 times faster than a ~1.2 TH/s Bitaxe purely from the hashrate difference.
  • An Antminer S21 at ~200 TH/s: roughly 86 years expected time, cutting the timeline of a ~110 TH/s S19 by almost half thanks to its higher hashrate.
  • A small farm of 25 S21 units (~5 PH/s): share rises to about 5.6 × 10⁻⁶, bringing expected time down to roughly 3.4 years and taking solo mining into a far more tangible statistical horizon, even though it remains high-variance.

The Break-Even Question: Electricity, ASIC Cost and Expected Value

An Antminer S21 draws roughly 3,500 watts. At an indicative household rate of around $0.10 per kWh (electricity prices vary hugely by region and change over time, so swap in your own tariff), that is about $8.40 a day. The correct economic comparison is not to multiply that spend by an 86-year expected wait and stack it against an unpredictable future block reward, it is to compare the daily cost with the daily expected value of your hashrate under today's difficulty, reward and price. In solo mining that expected value is concentrated in extremely infrequent payouts: you can go years without receiving anything and, if you do find a block, receive almost the entire reward at once. The honest way to use these numbers is not to calculate a guaranteed payback period, it is to size your exposure: treat solo mining hashrate as a small, clearly-labelled allocation toward a long-shot outcome, funded by hardware and power whose cost you are comfortable assuming regardless of the result.

So What Are Realistic Bitcoin Solo Mining Odds for You?

All of the figures above are averages, and averages hide the shape of the actual probability curve. Block discovery behaves like a Poisson process, so an expected time is not a predicted date, it is the mean of a highly variable distribution. Under steady conditions, a ~200 TH/s S21 with an expected time near 86 years does not need to wait 86 years to "get a shot": its probability of finding at least one block within a year runs around 1.2%. For the small 5 PH/s farm with an expected time of ~3.4 years, the probability of finding at least one block in year one runs around 26%, and over the full 3.4 years it climbs to roughly 63%, not 100%. This is also where solo mining's fundamental difference shows up: it does not turn your hashrate into a frequent stream of shared payouts, it concentrates the outcome into a very low-probability, high-magnitude event. On OwnBlock, if your work finds a block, 98% of the corresponding reward is paid directly to your Bitcoin address via the coinbase transaction, no KYC, no custodial balance. Solo mining does not, by itself, increase the expected value of your hashrate; what changes radically is the distribution of payouts and the variance you accept.

Turn Your Hashrate Into a Real Answer, Not a Guess

Every number in this article, the 86 years, the 3.4 years, the thousands of years, depends on your actual hashrate and today's network conditions, both of which change over time. Rather than reusing someone else's example, plug your own rig's hashrate into OwnBlock's free calculator to get your personalised expected time to a block and a day-by-day, month-by-month, year-by-year probability breakdown based on current network conditions. If the numbers make sense for your setup, OwnBlock's Bitcoin solo mining pool lets you point that hashrate at the network directly; if you find a block, you receive 98% of the corresponding reward directly, with no custodial balance in between. Bitcoin solo mining odds remain extremely low for a single rig against a 900+ EH/s network, but they are not a mystery either, and now you have the actual figures to decide for yourself.