About WattCost.org

WattCost.org is a free electricity cost calculator that helps you understand what your home appliances really cost to run.

There's no sign-up, no account, and no personal data collected. All calculations happen in your browser.

How it works

Enter your appliance's wattage and how many hours per day you use it. WattCost calculates the cost per hour, day, month, and year using your local electricity rate.

Electricity rates are pre-loaded based on your browser's language setting and can be changed to any country, US state, or Canadian province — or you can enter your exact rate from your bill.

How we stay free

WattCost.org is supported by Google AdSense advertising and may include affiliate links. We earn a small commission if you purchase a product through a link on this site, at no extra cost to you. This never influences our content or calculator results.

Data sources

US electricity rates are sourced from the EIA (U.S. Energy Information Administration) Electric Power Monthly. International rates are sourced from Eurostat and IEA published data. Rates are reviewed and updated periodically.