Find what may be driving your electric bill—and what to investigate next.

Start with a whole-home estimate, then use focused calculators to improve the appliance assumptions that matter most.

Audit my electricity useCalculate an appliance

No account required. Your inputs stay in your browser. Estimates use government electricity-rate data and transparent methodology.

Data sources:EIA (US)

EIA data period: May 2026EIA source release date: WattItCost site update date:

What are you trying to understand?

My electric bill seems high

Compare major appliance estimates with billed kWh and find what is still unexplained.

Start the Home Audit

I want one appliance’s cost

Estimate an appliance from watts and runtime, annual kWh, or cycle use where supported.

Browse calculators

I want to compare electricity rates

Review EIA state residential averages, then use your own bill rate when available.

Compare electricity rates

Popular appliance calculators

Use these after the Home Audit identifies a load that needs a better estimate.

Dehumidifier Running Cost Calculator

Estimate electricity cost from your entered use

Calculate an appliance

AC Running Cost Calculator

How much does your AC add to your bill?

Calculate an appliance

Space Heater Running Cost Calculator

How much does your heater add to your bill?

Calculate an appliance

Listed Appliance Cost

Estimate a subtotal for the appliances you list

Calculate an appliance

What may be using the most electricity?

High power matters, but runtime and cycling matter too. Heating, cooling, water heating, drying, refrigeration, dehumidification, pumps, and continuous loads are practical places to look.

Read what uses the most electricity

Electricity rates and methodology

State rates are reference averages rather than customer tariffs. Use the rate from your bill when possible, and review how every estimate is calculated.

View electricity ratesRead the methodology

Useful guides

Use these guides to organize an investigation without treating an estimate as a diagnosis.

Why Is My Electric Bill So High?

Separate higher kWh from rate, billing-period, fee, weather, and schedule changes.

What Uses the Most Electricity in a Home?

Review the household loads that can combine high power with long or frequent runtime.

Private inputs and transparent assumptions

WattItCost is an independent project. No account is required, household inputs stay in your browser, and estimates show their assumptions and limitations.

WattItCost is an independent appliance energy-cost calculator project.

About WattItCost