About this calculator

Energy used = power (kW) × hours. Cost = energy × tariff. Useful for sizing solar, comparing appliances and budgeting heating.

How it works

Enter your power (w), hours per day, price per kwh and days. The result updates as you type. Nothing you enter is stored.

Limits

Results are theoretical and ignore installation method and grouping. Mains work must meet local wiring rules (BS 7671 in the UK).

Who it's for

Electricians, students and DIYers checking loads, cables and running costs.

Frequently asked questions

What does the kWh Energy Cost Calculator do?

Work out the running cost of any appliance from wattage, usage and price per kWh. Energy used = power (kW) × hours. Cost = energy × tariff. Useful for sizing solar, comparing appliances and budgeting heating.

Is the kWh Energy Cost Calculator free to use?

Yes. Every calculator on Calcurly.com is free, works in your browser without sign-up, and can be embedded on your own website.

How accurate is the kWh Energy Cost Calculator?

Results are calculated in real time using industry-standard formulas. Treat the output as a well-informed estimate — always cross-check with local regulations, product datasheets, or a qualified electrical professional before committing to a purchase or a job.

What inputs does the kWh Energy Cost Calculator need?

Enter values for: Power (W), Hours per day, Price per kWh, Days. Sensible defaults are pre-filled where possible so you can start with a single change.

Can I embed the kWh Energy Cost Calculator on my own website?

Yes — copy the iframe snippet at the bottom of this page, or use the Embed Generator to customise the size. The embedded version stays in sync with the live calculator on Calcurly.com.