Appliance Electricity Cost Calculator
What does that space heater, dehumidifier, or old freezer actually cost you? Enter its wattage and daily run time to get energy use and cost per month and per year.
This calculator assumes the appliance runs for the hours entered every day. The year below is a true 365-day year, and a month is an average month: the year divided by 12, or 30.42 days.
Your results
Worked example
A 1,500 W space heater runs 6 hours a day, every day, at the Ontario on-peak rate of $0.203 per kWh:
- Per day: 1.5 kW × 6 h = 9.0 kWh
- Per year: 9.0 kWh × 365 days = 3,285.0 kWh, costing 3,285.0 × $0.203 = $666.86
- Per month: the year divided by 12, so 3,285.0 ÷ 12 = 273.8 kWh (an average month of 30.42 days), costing 273.75 × $0.203 = $55.57
The same heater run only off-peak at $0.098 would cost $26.83 a month. When an appliance runs is worth as much as how long it runs, for anything that can be shifted.
How this calculator works
The year is a true 365-day year and the month is the year divided by 12, an average month of 30.42 days, so the monthly and yearly figures always agree with each other. The Ontario time-of-use presets (off-peak $0.098, mid-peak $0.157, on-peak $0.203 per kWh) are editable defaults only; they are the published delivery-exclusive energy rates at the time of writing and they change, so check your bill. Your bill's true per-kWh cost is higher once delivery, regulatory charges, and HST are spread across usage; dividing one month's total bill by its kWh gives your personal all-in rate, the best number to type into the rate field.
Comparing whole home heating options? The Heating Cost Comparison Calculator puts gas, electric, heat pump, oil and propane side by side at your own prices, and the Heating Degree Days Calculator shows how cold a period really was.
Common questions
The label says amps, not watts. How do I convert?
Multiply amps by volts. On a standard Canadian household circuit at 120 V, a 12.5 A appliance draws about 1,500 W. Large appliances on 240 V use 240 in the same multiplication.
My fridge is rated 150 W but does not cost this much. Why?
Compressors cycle on and off, so a fridge's rated watts are its draw while running, not a continuous draw. For cycling appliances, estimate the share of the day the compressor actually runs, often a third to a half, and scale the hours accordingly.
Estimates only. Results are provided for planning purposes and use the wattage, hours, and rate entered. Preset rates are editable defaults labelled on this page; check your bill for your current rate. Actual costs vary with cycling, standby draw, and the other charges on your bill. Mississippi Maple accepts no liability for decisions made using this calculator.