Check a billCalculatorkWh × p/kWhStanding charge add-on
kWh to cost calculator for UK energy bills
Use this quick check to estimate the variable usage part of the bill, then add standing charge separately for a more useful subtotal.
kWh to cost calculator
Usage cost
£75.00
Standing charge
£15.90
Estimated subtotal
£90.90
Use this as a sense check. Some bills include more than one unit rate, an Economy 7 split, account adjustments or balances from earlier periods.
When this calculator is useful
- Checking whether the variable part of the bill feels broadly right.
- Comparing one period against another when the tariff stayed the same.
- Working out whether a bill is mostly a usage problem or mostly a standing-charge problem.
- Preparing a clearer supplier message with your own rough maths attached.
When it is not enough
- The bill covers a tariff change mid-period.
- You are on a multi-rate tariff such as Economy 7.
- The supplier is correcting earlier estimated bills.
- The monthly payment is the problem rather than the billed usage itself.
What to check after the maths
- Look at the bill dates and billed days.
- Check whether the reading used was actual or estimated.
- Confirm the meter serial number matches your meter.
- Check whether the bill shows one unit rate or multiple rates.
- Only then decide whether you need the complaint route.
A calculator is strongest when paired with photos of the meter, the full statement PDF and a short note showing what you think the corrected amount should be.