Disclosure: this is the account of Mineshop.eu, an EU mining-hardware shop based in Ireland. We sell home miners, so we have a commercial interest. The calculator below is free and open source: no sign-up, no cookies, and nothing you type leaves your browser.
The question we hear most from UK buyers of small miners is not about hashrate. It is: what will this add to my electricity bill? Here is how to get a real answer.
1. Measure at the wall#
Plug the miner into a plug-in power meter for 24 hours. Nameplate figures are often off, and tuning, fan speed and firmware all change the draw.
2. Turn watts into kWh#
kWh per year = watts × hours per day × 365 ÷ 1,000
3. Multiply by your unit rate#
The Ofgem price cap for 1 October to 31 December 2026 averages 26.32p per kWh for electricity (Direct Debit). You pay the standing charge whether you mine or not, so leave it out.
| Miner (typical draw) | kWh a year, running 24/7 | Cost a year at 26.32p |
|---|---|---|
| Bitaxe Gamma (about 17 W) | 149 | about £39 |
| NerdQaxe++ (about 80 W) | 701 | about £184 |
| Avalon Nano 3S (140 W) | 1,226 | about £323 |
For scale: a 3 kW ASIC uses 72 kWh a day, about £18.95 a day (roughly £570 a month) at the same rate. That is why full-size ASICs rarely make sense on a UK home tariff.
What Economy 7 changes#
On a two-rate tariff, a miner that runs 24/7 only gets the cheap rate during the off-peak window. With 7 off-peak hours, that is 7/24, about 29% of its energy.
Example rates (use the ones on your bill): 30p day, 15p night. The blended rate is (7 × 15 + 17 × 30) ÷ 24 ≈ 25.6p per kWh, so an Avalon Nano 3S costs about £314 a year instead of £323. Running it only off-peak cuts that to about £54 a year, but it then mines only 29% of the time.
Heat#
Almost every watt ends up as heat in the room. If you would otherwise heat that room with a plain electric heater, the miner's heat replaces it watt for watt. Against a heat pump or a gas boiler it is worth less, and in summer it is just extra heat.
A reality check#
This is a cost calculator, not a profit calculator. A small solo miner is a lottery ticket for a whole block, not an income.
Free calculators#
- UK, price cap or Economy 7: https://mineshop007.github.io/uk-home-miner-running-cost/ (source code and tests: https://github.com/Mineshop007/uk-home-miner-running-cost)
- France and other EU countries, Base or Heures Creuses (in French): https://mineshop007.github.io/cout-mini-mineur/
Source for the cap: Ofgem, Energy price cap unit rates and standing charges.
A longer UK write-up covers legal status, noise, heat and import VAT when buying from the EU (including from us): ASIC Bitcoin Mining in the UK 2026: legal, cost and setup guide.
Questions and corrections are welcome.
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