Money Worked Out

Electricity cost calculator UK

Estimate what one appliance costs to run. Enter its power and running time, or the energy used per cycle, with your electricity rate including VAT.

Example: cost per use

£0.50

£0.50 a day · £15.00 per 30-day month

£182.50 a year, at 1 use every day.

Illustrative values. Enter the rate from your bill.

Amounts are rounded to the nearest penny.

Your appliance

Use average power if it varies during use.

Changing the unit keeps the number you entered.

Changing the unit keeps the number you entered.

Use your bill rate including VAT. The starting rate is illustrative.

This frequency repeats every day in the totals.

Show the working
  1. 2,000 W ÷ 1,000 × 1 hours = 2 kWh per use.
  2. 2 kWh × 25p per kWh ÷ 100 = £0.50 per use, rounded.
  3. Multiply the unrounded cost per use by 1 uses a day: £0.50 a day.
  4. Multiply the unrounded daily cost by 30 for a month (£15.00) or 365 for a year (£182.50).

The rate and daily use stay the same throughout each period. Costs are calculated before rounding.

This is information, not financial advice.

Which figures to enter

Choose power and time if you know the appliance's watts (W) or kilowatts (kW) and how long it runs. Power measures how quickly it uses energy. A kilowatt is 1,000 watts.

Choose energy per use if you have a meter reading or an energy label in kilowatt-hours (kWh). Enter the energy for one use or cycle. This mode uses that figure directly, without multiplying it by running time. If a label gives energy per 100 cycles, divide it by 100 first.

Use the unit rate from your bill, in pence per kWh, including VAT. It works with your own tariff anywhere in the UK, including Northern Ireland. The starting figures are illustrative examples, not a current tariff or a particular appliance's measured use.

When power changes during use

The power-and-time estimate assumes the appliance draws the entered power throughout the use. The rating on an appliance can show its maximum power. Fridges, ovens and heaters with thermostats switch on and off, so multiplying that rating by the whole time can overestimate their energy use.

For appliances that cycle, use measured kWh or the label's energy for the relevant cycle where available. Different settings and conditions can change consumption.

How the costs are worked out

In power mode, kilowatts multiplied by hours gives kWh per use. Energy per use multiplied by your unit rate gives the cost. The calculation method explains our approach to estimates and rounding.

Daily cost repeats the entered number of uses each day. Monthly cost covers 30 days; yearly cost covers 365 days. Each total is rounded separately, so tiny costs still count towards later totals even when the cost per use displays as zero.

Standing charges are separate daily charges and are excluded. These results are appliance costs, not a whole bill. Discounts and changing unit rates are excluded too. If your rate changes by time or date, calculate each period separately.

To compare two running-cost estimates, use the percentage calculator to find the percentage change. Browse all calculators for other everyday calculations.

Sources and your information

The Energy Saving Trust's energy jargon guide explains watts, kilowatts and kilowatt-hours. Ofgem's bill guide explains unit rates and standing charges.

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