General tools
Electricity Cost Per Hour Calculator UK
Use this general calculator for any appliance when you know the wattage.
Estimated running cost
- Per hour
- 24.67p
- Per day
- 24.67p
- Per week
- £1.73
- Per month
- £7.40
- Per year
- £90.05
Formula: watts ÷ 1,000 × 1 hour × electricity price.
Cost table
| Scenario | Power | Use time | Cost at 24.67p/kWh |
|---|---|---|---|
| 100W for 1 hour | 100W | 1 hours | 2.47p |
| 500W for 1 hour | 500W | 1 hours | 12.34p |
| 1,000W for 1 hour | 1,000W | 1 hours | 24.67p |
| 2,000W for 1 hour | 2,000W | 1 hours | 49.34p |
Formula
watts ÷ 1,000 × 1 hour × electricity price = running cost
For example, a 1,000W appliance used for 1 hour at 24.67p/kWh costs 1 x 1 x 24.67p = 24.67p.
Ways to reduce the cost
- Check appliance labels for rated watts.
- Use a plug-in energy meter for real-world power draw.
- Remember that thermostats and cycles can reduce average usage.
- Enter your actual tariff for a more accurate estimate.
FAQs
How do I convert watts to cost per hour?
Divide watts by 1,000, then multiply by pence per kWh.
What does kWh mean?
A kilowatt-hour is 1,000 watts used for one hour.
Does standing charge matter?
Standing charges affect the bill but not the marginal appliance running cost.
Can this handle any appliance?
Yes, if you know the approximate wattage and usage time.
Last reviewed 3 May 2026. Source: Ofgem energy price cap. Figures are estimates. Actual prices vary by region, supplier, tariff, payment method and meter type.