Appliance Running Cost Calculator

How it works

Energy per day (kWh) = watts ÷ 1000 × hours per day. Yearly energy = daily energy × days used per year. Cost = energy × your rate. The monthly figure is the yearly cost divided by 12.

Worked example, step by step

Take the defaults above: a 1,500 W appliance used 3 hours a day, every day, at $0.17/kWh.

Energy per day = 1,500 ÷ 1,000 × 3 = 4.5 kWh.

Cost per day = 4.5 kWh × $0.17 = $0.77.

Energy per year = 4.5 kWh × 365 = 1,642.5 kWh.

Cost per year = 1,642.5 kWh × $0.17 = $279.23, or about $23 a month.

The single biggest lever is the wattage: halve it to 750 W and the yearly cost halves to about $140. The second biggest is hours of use — cutting from 3 hours a day to 1 drops the yearly cost to roughly $93.

How to get an accurate number for YOUR appliance

The wattage on the label is usually the maximum draw, not the average — which matters most for appliances that cycle on and off rather than running steadily.

Steady-draw devices (heaters, lights, chargers, a running motor): the label wattage is close to reality, so enter it directly.

Cycling devices (fridges, freezers, air conditioners, thermostats): these switch on and off to hold a temperature, so their average draw is well below the label number. For these, it is more accurate to use the appliance's published kWh-per-year figure from its energy label than to guess wattage × hours — or use a dedicated calculator (we have ones for fridges, freezers, and AC that handle this for you).

For a truly exact figure, a plug-in energy monitor (a "kill-a-watt" style meter) measures real consumption over days and removes all the guesswork. If you only have amps and volts on the label, watts = amps × volts.

Don't forget standby: many devices draw 1–5 W around the clock even when "off". Enter a low wattage at 24 hours a day to see what that phantom load costs over a year — often more than people expect.

Frequently asked questions