WattPocketTry the calculator

Electricity cost calculator

Start with a common appliance or enter any wattage. The result updates as you type and stays on your device.

W
hr
¢/kWh
$45.19/ month
$1.51/ day
$549.84/ year

This setup uses about 240 kWh in a 30-day month.

Default rate: U.S. residential average for 2026-04. Replace it with the price on your bill for a closer estimate.

One formula, four inputs.

Electric bills charge for energy, not just power. Converting watts to kilowatts connects the appliance label to the rate on your bill.

Daily cost(watts ÷ 1,000) × hours × rate per kWh
  • Use active runtime, not simply 24 hours.
  • Enter cents per kWh exactly as shown on the bill.
  • Treat cycling appliances as an estimate or measure them.

Start with a popular check

Make the estimate fit your home.

  1. 01
    Find the input watts

    Use the appliance label or manufacturer specification. For variable equipment, a plug-in meter gives a better average.

  2. 02
    Estimate active hours

    A refrigerator is plugged in all day but its compressor cycles. Count operating time, not connection time.

  3. 03
    Use your effective rate

    Divide usage-based charges by billed kWh if your plan includes tiers or time-of-use pricing.