Find your calculator

Electricity Cost Calculator

Estimate appliance energy use in kWh and electricity cost from power, daily hours, days used, and your tariff.

Your inputs

Adjust the example values, then calculate.

Your result

Review your calculated values below.

Ready when you are.

Choose Calculate to see your result.

How to use this calculator

  1. Enter your values in the labeled fields, keeping the displayed units.
  2. Choose Calculate or press Enter in a single-line field.
  3. Review the result and the assumptions below before using it.

Formula and method

Energy (kWh) = watts / 1000 × daily hours × days. Cost = energy × tariff.

Worked example

A 1,000 W appliance used two hours daily for 30 days consumes 60 kWh and costs 12 at 0.20/kWh.

What the result assumes

Use average power for devices that cycle on and off. Fixed charges and time-of-use pricing are excluded.

Common question

Is the wattage on the label always the actual use?

It may be rated or maximum power. A measured average gives a better estimate for variable-load appliances.

Reference

U.S. Department of Energy: energy use and cost calculations