kWh cost calculator
Turn a known energy usage figure — from a smart meter, an appliance's energy label, or a bill — into a cost, using your electricity price.
Result
Cost
How to use this calculator
- Enter the energy used, in kWh — from a smart meter reading, a bill, or an appliance's stated energy use.
- Enter your electricity price per kWh.
- Read the cost.
Assumptions
- Uses a flat price per kWh — does not model time-of-use or tiered tariffs.
Technical details: what the fields mean
- Energy used
kwhUsed - Energy used, in kilowatt-hours — the unit your electricity bill and meter both use.
- Electricity price
pricePerKwh - Your electricity price per kWh, from a recent bill or your tariff's rate.
Methodology
Cost = energy used (kWh) × price per kWh — a direct multiplication.
Worked example
150 kWh at 27p/kWh
Inputs: kwhUsed=150, pricePerKwh=0.27
Result: £40.50
Practical guidance
- Use your smart meter's in-home display or app to read actual kWh usage for a specific period, then apply your tariff rate here.
Common mistakes
- Using a different period's usage figure against the wrong tariff rate — check both are for the same billing period if comparing to an actual bill.
FAQs
How do I convert kWh to cost?
Multiply the kWh figure by your price per kWh — this calculator does that directly.