Electric bill calculator
Build a list of what runs in your home. The estimate updates as you go, ranks your biggest loads, and stays saved in this browser for next time.
- Wh$32.76
- Wh$43.68
- Wh$19.66
- Wh$73.71
- Wh$27.3
Your list and rate are saved in this browser only. Privacy
Reading the estimate
Each row is watts × hours per day × quantity × 30 days. The bar shows each device's share, so the biggest costs stand out. The example wattages are round starting figures: replace them with the numbers on your own appliances' labels, or better, a plug-in energy meter reading.
Heating, cooling and water heating usually dominate. Their "hours per day" should be the time the element or compressor actually runs, which is often far less than the time the thermostat is on.
Tiered and time-of-use rates
This estimate uses one flat rate. Many utilities charge differently: time-of-use plans price each kWh by the hour it's used, and tiered plans price kWh in blocks, charging the higher rate only on usage past each threshold. US income tax brackets run on that same marginal logic, and ahaboo has a narrated explainer on how they work. For a tiered plan, work out your blended rate (energy charges ÷ kWh) from a recent bill and enter that.
Compare with your bill
Your bill lists the kWh you actually used. If the estimate is much lower, something is running longer than you think (an old second fridge, a well pump, a pool pump, electric baseboard heat). If it's much higher, your hours are probably too generous.
Questions people ask
How is an electric bill calculated?
Most residential bills are kWh used × energy rate, plus per-kWh delivery charges, plus a fixed monthly customer charge and taxes. Some utilities use tiered or time-of-use rates.
Why is my estimate different from my bill?
Appliances rarely draw their nameplate watts all the time. Refrigerators, heaters and air conditioners cycle on and off. Use a plug-in energy meter to measure real kWh for the biggest loads.
What uses the most electricity at home?
Heating and cooling are usually the largest loads, followed by water heating, then appliances such as dryers and refrigerators. Use the list here to see where your own home ranks.