WattItCost
Stop guessing what your appliances add to your electricity bill. Our free calculators use real electricity rates to show you exactly what each appliance costs per hour, day, month, and year.
By the WattItCost Team
Every calculator uses official government electricity rate data, updated quarterly. All calculations happen in your browser — we don't store your inputs or results.
How It Works
Three simple steps to know your exact electricity costs
Pick Your Appliance
Choose from our library of calculators — space heaters, dehumidifiers, or any appliance.
Set Your Details
Adjust wattage, hours of use, and select your state for accurate local electricity rates.
See Your Costs
Get instant results — per hour, day, month, and year — with tips to save money.
Space Heater Calculators
Find out exactly how much your space heater costs to run, compare heater types, and right-size your next purchase.
Dehumidifier Calculators
Calculate dehumidifier running costs, compare models, and find the right capacity for your space.
All Appliance Tools
Compare any two appliances or estimate the total energy cost of everything in your home.
Why Trust WattItCost
Official Government Data
Every calculation uses electricity rates from the EIA and Ofgem — the same data utilities use.
Updated Quarterly
Rates are reviewed and refreshed every quarter so your estimates stay accurate.
100% Private
All calculations happen in your browser. We never store your inputs or results.
Free Forever
No accounts, no paywalls, no hidden fees. Just accurate electricity cost estimates.
Coming Soon
We’re building calculators for these appliances next.