Home Electricity Cost Audit

Estimate which entered appliances may be using the most electricity

Quick Answer

This is an estimate based on the entered information. It can rank modelled appliance use and compare it with bill kWh, but it is not a professional inspection or certification and does not diagnose your home.

Electricity rates: U.S. EIA, May 2026

WattItCost is an independent appliance energy-cost calculator project.

Read the full calculation methodologyHow we calculate →
Choose your estimate detail

Start with major household loads and visible assumptions. You can edit every value or switch to Detailed estimate without losing valid entries.

Set your electricity details

Choose a state-average rate or enter your own, then use the same number of days shown on your electric bill.

Select a state to load its average residential rate, or enter your own electricity rate below.

Add your appliances

Select the appliances you use, then choose the input method that matches what you know: watts and daily runtime, annual label kWh, or kWh per cycle.

Starting assumption

Wattage mode is a rough estimate for cycling or variable-power appliances because nameplate watts are not continuous average use.

$33.19

estimated for this period

Starting assumption

Use the annual kWh from the appliance's EnergyGuide label or manufacturer specifications when available.

$9.09

estimated for this period

2 appliance(s) selected for a 30-day estimate at $0.18/kWh.

See what may be using the most

Generate a ranked estimate from the appliances and usage you entered.

How the Home Electricity Cost Audit Works

Set the billing-period days, select a state rate or enter your own electricity rate, and add the appliances you want to estimate. Use watts and daily runtime for steady loads, annual label kWh for appliances such as refrigerators, or kWh per cycle for washers, dryers, and dishwashers. When bill kWh is entered, electricity not yet explained is the nonnegative remainder after subtracting modelled appliance kWh. Modelled coverage is appliance kWh divided by bill kWh and is capped at 100%. When bill kWh is omitted, the tool shows only the appliance estimate. Total bill amount is displayed separately because utility bills can include charges this simple energy estimate does not model.

Frequently Asked Questions

What does electricity not yet explained mean?
It is the nonnegative remainder after subtracting modelled appliance kWh from the bill kWh you entered. It can reflect appliances not added, heating or cooling cycling, water heating, standby loads, or differences between estimated and actual use.
Why can the modelled estimate be higher than my bill kWh?
Nameplate wattage is often higher than average operating power, many appliances cycle on and off, and runtime or cycle entries can be too high. In that case electricity not yet explained stays at zero; review watts, runtime, cycle frequency, and cycling appliances.
Does this replace a professional home energy audit?
No. It is an estimate based on the appliances and usage you enter. It is not a professional inspection or certification and does not diagnose your home.
Why is my total bill different from the modelled energy-cost estimate?
The estimate applies one electricity rate to modelled appliance kWh. Your bill may also include appliances not added, fixed fees, taxes, time-of-use or tiered pricing, demand charges, credits, and other tariff details.
Data sources:EIA (US)

Citation-ready summary

Summary

This is an estimate based on the entered information. It can rank modelled appliance use and compare it with bill kWh, but it is not a professional inspection or certification and does not diagnose your home.

Formula

Watts mode uses (watts ÷ 1,000) × hours/day; EnergyGuide mode uses annual label kWh ÷ 365; per-cycle mode uses kWh/cycle × cycles/week ÷ 7. Daily kWh is multiplied by billing-period days and the electricity rate.

Data used

Calculator results use user-entered wattage and usage hours, combined with residential electricity rates for the selected U.S. state or the rate entered from a utility bill.

Sources

EIA Electric Power Monthly Table 5.6.A residential

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

Limits

These estimates do not reproduce a utility bill. Actual costs depend on your tariff, taxes, appliance cycling, efficiency, and how you use the appliance.