Estimate what it costs to run an appliance, from its wattage, how long you use it, and your electricity rate.
Energy usage in kilowatt-hours is calculated as kWh = watts ÷ 1000 × hours used — converting an appliance's power rating (in watts) and how long it runs into the unit your electricity bill is actually priced in.
That kWh figure is then multiplied by your entered rate per kWh to get the cost for that usage period, which is then scaled up proportionally to show estimated monthly and yearly costs based on the same usage pattern continuing.
All figures are currency-agnostic — enter your electricity rate in whatever currency your actual bill uses, and the cost results will be in that same currency, since the calculation is a pure multiplication that doesn't care what currency symbol is attached to the rate.
Check the appliance's label, spec sheet, or manual — most appliances list their power rating in watts. If only amps and voltage are given, watts = amps × voltage.
On your electricity bill, usually listed as a rate per kWh or per unit — enter that exact rate and the calculator will use your own currency automatically.
By scaling up your entered usage period proportionally — if you calculate cost for one day of use, the monthly and yearly figures assume that same daily pattern continues consistently.
No — it uses a single flat rate per kWh that you enter. If your utility charges different rates at different usage tiers or times of day, calculate each tier separately and add the results together.
