Electricity Cost Calculator
Find out what any device costs to run: enter its wattage, how long you use it and your electricity price.
- Per day, month & year
- kWh used
- Your own rate
- With working
Electricity cost of an appliance
Fill in the boxes. The answer appears as you type.
How to calculate electricity cost
Electricity is billed in kilowatt-hours (kWh): 1,000 watts used for one hour. Multiply a device’s power in watts by the hours you use it, divide by 1,000 to get kWh, then multiply by your price per kWh. A 1,500 W space heater used 3 hours a day uses 4.5 kWh, costing about $0.77 a day at $0.17/kWh, or around $23 a month. The default price is close to the US average residential rate; replace it with the rate on your bill.
How to use Electricity Cost Calculator
- Find the wattage on the device label or manual (or measure it with a plug-in meter).
- Enter the hours you use it per day.
- Enter your electricity price per kWh from your bill.
- Read the cost per day, month and year, and the kWh used.
Typical appliance wattages
- Space heater 750–1,500 W · window AC 500–1,500 W · central AC 3,000–5,000 W.
- Gaming PC 300–700 W under load · laptop 30–90 W · TV 50–200 W.
- Refrigerator ~150 W average (it cycles on and off) · LED bulb 8–12 W.
- EV level 2 charging 7,000–11,500 W.
Why use this electricity cost calculator
- Answers as you typeNo Calculate button. Change any number and every result updates instantly.
- Shows the workingEach answer has a plain-English sentence, the steps and a formula for Excel or Google Sheets.
- Any applianceHeaters, air conditioners, gaming PCs, EV chargers, fridges and lights.
- PrivateYour numbers are calculated on your device and never sent anywhere.
Common uses
- Space heaters and AC. See the real cost of heating or cooling a room.
- Gaming PCs and crypto rigs. Running cost under load.
- Comparing appliances. Is an efficient model worth it?
- Budgeting. Estimate seasonal bill changes.
More calculators: percentage, discount, hours and time card calculators. Browse all everyday calculators.
Example: a gaming PC
450 W × 4 h = 1.8 kWh a day × $0.17 = $0.31 a day ≈ $9.31 a month ≈ $111.69 a year.
What to expect from the result
Many appliances do not draw their rated wattage all the time (fridges and AC cycle). For accuracy, measure actual use with a plug-in energy meter. Time-of-use and tiered tariffs are not modelled.
Electricity Cost Calculator questions
How do I calculate the cost of running an appliance?
Watts × hours ÷ 1,000 = kWh; kWh × price per kWh = cost.
How much does it cost to run a space heater?
A 1,500 W heater costs about $0.26 an hour at $0.17/kWh, or about $23 a month at 3 hours a day.
What is the average price per kWh in the US?
Around 16–18 cents for residential customers in 2026, varying widely by state. Use the rate on your bill.
How many kWh does a house use per month?
The average US home uses roughly 850–900 kWh a month.
Where do I find an appliance’s wattage?
On the rating label (often on the back or underside) or in the manual. If it lists amps, multiply amps by 120 volts.