This is a small point that changes the answer, and almost every mining calculator gets it wrong — some by including it, others by ignoring it entirely.
A UK electricity bill has two parts. The unit rate, charged per kWh you consume, and the standing charge, a fixed daily fee you pay simply for being connected. On the Octopus Agile tariff in Eastern England today, that standing charge is 48.79p a day, or about £178 a year.
The question is what to do with that £178 when working out whether mining pays.
The answer is nothing
You pay it whether the rig runs or not. It is not caused by mining, it does not increase because of mining, and it does not disappear if you stop. It is what economists call a sunk cost, and the entire point of a sunk cost is that it should play no part in a decision about what to do next.
The only question that matters is whether the rig earns more than the power it draws. The standing charge sits outside that question entirely.
Put concretely. Suppose your rig nets £0.40 a day after electricity. If you subtract the 48.79p standing charge you get minus 9p, and you conclude mining is loss-making and switch off. But switching off does not save you 48.79p — you still pay it. All you have done is give up 40p of genuine profit.
The correct comparison is not "does mining cover all my electricity costs?" It is "am I better off with the rig on or off?" Answer: £0.40 better off with it on.
Where calculators go wrong
Two failure modes, pulling in opposite directions.
Subtracting it from profit. This makes marginal setups look loss-making when they are not, and leads people to switch off rigs that were making them money. Most common on UK-focused calculators, where the author knows standing charges exist and reaches for the obvious treatment.
Ignoring it completely. Standard on American calculators, since US utilities structure bills differently. This is accidentally correct for the switch-on decision, but leaves people with no idea what their actual annual electricity cost is.
The right treatment is to show it — below the line, clearly labelled as payable regardless. That is what our calculator does. Profit from mining is one number; the standing charge is a separate fact about your bill.
When it does matter
Three exceptions, and they are real.
A separate supply. If you are considering a dedicated meter for a mining shed or outbuilding, that is a new connection with its own standing charge, caused entirely by the decision. It counts in full.
Choosing between tariffs. Standing charges vary between suppliers and regions, and a tariff with a lower unit rate but a higher standing charge may or may not suit a heavy user. When comparing tariffs, total cost is the right measure. When deciding whether to switch a rig on tonight, it is not.
Working out whether the whole venture is worthwhile. If you are asking "should I be doing this at all, given that I could stop paying for a supply entirely", the standing charge belongs in the sum. Almost nobody is genuinely in that position — you are not disconnecting your house — but the logic is sound if you are.
Why this is worth the pedantry
Because UK mining is marginal, and marginal decisions are precisely where accounting errors change behaviour. At 30p per kWh the answer is no regardless of how you treat the standing charge. At 12p it is a comfortable yes either way. It is in the band between, exactly where most UK miners sit, that a 48.79p misallocation flips the sign on the result.
And it generalises. The same reasoning applies to your broadband, your rent, and the cost of the card if you already own it. None of it belongs in the decision about whether to switch on tonight. What belongs is the electricity the rig will actually draw, and what it will actually earn.
Standing charge of 48.79p per day taken live from the Octopus Agile tariff for Eastern England on 14 August 2026. Standing charges vary by region, supplier and payment method.