DollarWise

Free Electricity Cost Calculator

October 12, 2026 · 2 min read · By the DollarWise team

How it works

Enter an appliance’s wattage, how many hours it runs each day, and your electricity price per kWh. The calculator shows the energy it uses each month and exactly what it costs per day, per month, and per year.

Electricity Cost Calculator

See what any appliance really costs to run — per day, per month and per year.

100% Free Forever No Sign-up No Credit Card Private — files never leave your browser Unlimited Use

1 Pick an appliance or enter watts

Wattage is printed on the label or plug of almost every appliance.

2 Usage and price

Find your rate on your electricity bill — the US average is about $0.17 per kWh.

3 See the running cost

💡 Running cost

🎉 Free forever. No sign-up. No credit card. No limits.

This calculator runs entirely in your browser — check every appliance in your home and find the energy hogs.

Everyday uses

  • Bill surprises: find out whether the space heater, AC, or old fridge is behind a high electricity bill.
  • Buying decisions: compare the yearly running cost of two appliances before choosing the efficient model.
  • Home office: work out what your laptop, monitors, and lights cost per month when you work from home.
  • Renting and roommates: estimate a fair share of the power bill for a heater, AC unit, or gaming PC.

Frequently asked questions

How do I find an appliance’s wattage? Check the label on the back, bottom, or plug — it is usually printed as “W” (for example 1500W). If only amps and volts are shown, multiply them together to get watts.

What exactly is a kWh? A kilowatt-hour is 1,000 watts running for one hour. Your bill charges per kWh, so a 1500W heater running 2 hours uses 3 kWh.

Why is my real bill a bit different? Some appliances cycle on and off — a fridge’s compressor does not run constantly — and many bills add fees or tiered rates. Treat the result as a close estimate, and adjust the hours to match real usage.