The three numbers you need
- How much electricity you use, in kWh.
- Your unit rate — the price per kWh, in pence.
- Your daily standing charge, in pence per day (if you want the full picture).
The calculation
Multiply the kWh you used by your unit rate to get the energy cost. Then add the standing charge for the number of days in the period.
For example, using 8 kWh in a day at 25p per kWh costs £2.00. Add a 50p standing charge and the estimated total for that day is £2.50.
Where to find your numbers
Your unit rate and standing charge appear on your bill or in your supplier's app. Your usage is on your bill, smart meter display or online account.
Why it's an estimate
Bills can include adjustments, different rates at different times, VAT treatment and estimated meter readings. A calculator gives a useful guide rather than an exact bill.