Electricity Cost Calculator
Running cost of any appliance
Curious what an appliance costs to run? Enter its wattage, how long it runs each day and your electricity rate to see the monthly and yearly cost.
Finding the wattage
Check the label or manual for watts (W). Running cost is watts ÷ 1000 × hours × rate. Always-on devices (fridges, pumps, space heaters) add up fast — this is a great way to hunt down energy hogs.
Watts, amps and kilowatt-hours
If a label lists amps instead of watts, multiply amps by your voltage (about 120V in the US) to get watts. Your utility bills in kilowatt-hours (kWh) — one kWh is a 1,000-watt appliance running for an hour. Check a recent bill for your exact rate; it often varies by season and time of day.
Finding the energy hogs
The biggest home energy users are anything that makes heat or runs constantly: heating and cooling, water heaters, electric dryers and refrigerators. Phantom "vampire" loads from devices on standby are small individually but add up. Run a few suspects through this calculator and you'll quickly see where the money goes.
Electricity Cost Calculator: frequently asked questions
How do I calculate appliance running cost?
Convert watts to kilowatts (÷1000), multiply by hours used, then by your electricity rate ($/kWh).
What uses the most electricity at home?
Heating and cooling, water heaters, dryers, and anything that runs constantly like refrigerators and pool pumps.
How do I convert amps to watts?
Multiply amps by volts. A device drawing 5 amps on a 120-volt US circuit uses about 600 watts. Divide watts by 1,000 to get kilowatts, then multiply by hours and your rate to find the cost.