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Running Cost Calculator

What a load actually costs to run. Enter the power and the hours, and put in your own unit rate from the bill -cost = kW × hours × unit rate. Useful for justifying a change to a client, or for settling an argument about the heater in the site cabin.

The load
Usage
Tariff

Cost

Effective power -
Energy per year -
Per hour running -
Per day -
Per month -
Per year -
Duty cycle is the one people forget. A 3 kW heater on a thermostat does not draw 3 kW all day - it cycles. Running the sum at 100 % when the real figure is 40 % overstates the bill by two and a half times, and it is the usual reason a predicted saving never shows up.
Worked example

A 3 kW heater, 8 hours a day, 5 days a week, cycling at 100 %, at 26p per kWh.

3 kW × 8 h = 24 kWh per day

24 × 26p = £6.24 per day

× 5 days × 52 weeks = £1,622 per year

An estimate based on the figures you enter. Real bills vary with tariff structure, time-of-use rates, VAT treatment and standing charges. Always check against an actual bill before relying on the number.