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Electricity Cost Calculator

Estimate how much an appliance or load costs to run from power, time and unit price.

This is a cost estimate. Actual use depends on duty cycle, tariff and appliance behaviour.

Notes and next steps

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How it works

Estimate electricity running cost from power, time, days and unit price.

Estimating method: kWh = W ÷ 1000 × hours × days. Cost = kWh × pence per kWh ÷ 100.

Worked example

1000 W for 4 hours a day over 30 days is 120 kWh. At 28p/kWh, cost is £33.60.

Common mistakes
  • Assuming an appliance runs at full power constantly.
  • Using the wrong tariff/unit price.
  • Forgetting standby or duty-cycle behaviour.
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