Electricity cost calculator

See what a space heater, AC unit or EV charger really costs you each month.

kW·hPh
Letters on the drawing match the letters next to the inputs.
W
h/day
days
$/kWh
Cost per month$7.65

Shopping list

  • Cost per year$92

How we got there

Energy per day
1.5 kWh
Energy per month
45 kWh
Energy per year
540 kWh

Results are estimates. Always check the coverage printed on the product and your local building code.

How it is calculated

Energy in kilowatt-hours is watts × hours of use ÷ 1,000. Multiply by days for the month and by your rate per kWh for the cost. For an accurate result, use the all-in rate from your bill, including delivery charges and taxes.

FormulakWh per day = watts × hours ÷ 1,000Cost per month = kWh per day × days × rate per kWh

Example

A 1,500 W space heater running one hour a day uses 45 kWh a month. At $0.17 per kWh that is $7.65 a month, or about $92 a year.

Tips from practice

  • Heaters cycle on and off with the thermostat, so they rarely draw full power all the time.
  • On time-of-use plans, run big loads off-peak.
  • The wattage is on the appliance label; 1 kW = 1,000 W.

Questions and answers

How much does a space heater cost to run?

A 1,500 W heater uses 1.5 kWh per hour: about 26 cents an hour at $0.17 per kWh.

What rate should I use?

Divide your last bill total by the kWh used. That includes delivery and taxes.

How much does it cost to charge an EV at home?

A typical 60 kWh charge costs about $10 at $0.17 per kWh, plus charging losses.

Found a mistake in a formula? Write to contact@planicalc.com