Electricity Cost Calculator
This electricity cost calculator estimates how much energy an appliance uses and what it costs to run per day, week, month and year from its power in watts, daily hours of use and your electricity rate.
About this tool
This electricity cost calculator estimates how much energy an appliance uses and what it costs to run per day, week, month and year from its power in watts, daily hours of use and your electricity rate.
How to use it
- Enter the appliance's power in watts, or pick a quick preset.
- Enter how many hours a day it runs.
- Enter your electricity rate per kWh or per MWh.
- Read the daily, weekly, monthly and yearly cost and energy use.
Good to know
- Energy per day (kWh) = watts × hours per day ÷ 1,000.
- Cost = kWh × price per kWh; a price per MWh is divided by 1,000 first.
- Example: a 1,500 W heater used 1 hour a day uses 1.5 kWh; at 0.15 per kWh that is about 82.13 a year.
- Monthly cost assumes 30 days and yearly cost 365 days.
- Presets include an LED bulb (10 W), laptop (60 W), TV (150 W), hair dryer (1,500 W), oven (2,000 W) and AC unit (3,500 W).
Runs entirely in your browser — nothing you enter is uploaded or stored.
Frequently asked questions
How do I calculate an appliance's electricity cost?
Multiply its wattage by the hours it runs, divide by 1,000 to get kWh, and multiply by your price per kWh.
Where do I find an appliance's wattage?
Check the label on the back or bottom of the device, or its manual. Chargers often list volts and amps; multiply them for an approximate wattage.
What is a kWh?
A kilowatt-hour is the energy used by a 1,000-watt device running for one hour. Electricity bills charge per kWh.
Why do appliances like fridges use less than their rating?
Fridges, AC units and heaters cycle on and off, so they draw full power only part of the time. Use the hours they actually run for a closer estimate.