HEATING
Space heater running cost
See how a common 1,500-watt heater changes your daily bill at different electricity rates.
Open heater calculatorHOME ENERGY, MADE CLEAR
Know what an appliance costs before the bill arrives.
Turn watts, hours, and your electricity rate into a clear daily, monthly, and yearly estimate. No signup. No guesswork hidden behind a form.
Editable local rate
Transparent formula
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QUICK ESTIMATE
Electricity cost calculator
Loading current EIA residential rates…
Per day$1.28
Per month$38.25
Per year$465.38
Formula
1.5 kW × 5 h × $0.17 = $1.28/day
| Appliance | Power | Use/day | Monthly | Yearly |
|---|
Add appliances to compare their running costs side by side.
01Find the wattage on the appliance label
02Use your bill or the latest EIA state average
03Compare appliances and share the result
START WITH THE BIG LOADS
Where home electricity use adds up
Heating, cooling, water heating, and EV charging can run for hours at a time. Start there before worrying about phone chargers and other tiny loads.
COOLING
Air conditioner running cost
Estimate the operating cost of a window unit and adjust the wattage to match your model.
Open AC calculatorELECTRIC VEHICLES
Home EV charging cost
Compare Level 2 charging sessions using your utility rate and charger power.
Open EV calculatorKITCHEN
Refrigerator running cost
Account for compressor cycling when estimating a refrigerator's energy use.
Open refrigerator calculatorLAUNDRY
Clothes dryer running cost
Estimate the cost per drying day and compare shorter or lower-heat cycles.
Open dryer calculatorQUICK REFERENCE
Typical appliance wattage
Use the nameplate wattage on your own appliance when available. These ranges are starting points for planning and comparison.
| Appliance | Typical watts | Common use | Cost guide |
|---|---|---|---|
| Portable space heater | 750–1,500 W | 2–8 hours/day | Calculate |
| Window air conditioner | 500–1,500 W | 4–12 hours/day | Calculate |
| Refrigerator | 100–250 W running | Cycles all day | Calculate |
| Electric clothes dryer | 2,000–5,000 W | 30–60 minutes/load | Calculate |
| Level 2 EV charger | 3,300–11,500 W | 1–8 hours/session | Calculate |
| Dishwasher | 1,200–1,800 W | 1–2 hours/cycle | Calculate |
| Electric oven | 2,000–5,000 W | 0.5–2 hours/use | Calculate |
| Desktop computer | 100–500 W | 2–10 hours/day | Calculate |
COMMON QUESTIONS
Electricity cost FAQ
Short answers to the questions that matter when turning appliance wattage into a realistic bill estimate.
How do I calculate the cost of running an appliance?
Divide watts by 1,000, multiply by hours used, then multiply by your electricity price per kWh. WattBill performs the calculation instantly.
Should I use my state average or my utility bill?
Your bill is more accurate. State averages from the EIA are useful when comparing locations or when your current rate is not available.
Why can actual appliance use be lower than its wattage label?
Many appliances cycle on and off or change power by operating mode. The label may show a maximum rather than an all-day average.
Does the estimate include taxes and fixed utility charges?
No. The calculator estimates energy charges from kWh use. Fixed customer charges, taxes, tiers, and demand charges may change the final bill.
THE SIMPLE MATH
What does a kilowatt-hour mean?
A kilowatt-hour (kWh) is the energy used by 1,000 watts running for one hour. A 1,500-watt space heater running for two hours uses 3 kWh.
Your result is an estimate. Real consumption can change as thermostats cycle, appliances use different modes, and utility bills add taxes or fixed charges.
Read our calculation methodology →