How to use the electricity cost calculator
- Choose a preset or enter the wattage. The watts are printed on the label or power adapter. If only amps are listed, multiply amps by volts (120 V for most US outlets, 240 V for dryers and ovens).
- Enter hours of use per day and how many days a month you use it.
- Enter your rate. Divide the total on your bill by the kWh used to get your all-in price per kWh, including delivery charges.
Electricity cost formula
Cost = kWh × rate per kWh
A kilowatt-hour (kWh) is 1,000 watts used for one hour. That is the unit your utility bills you for.
Worked example
A 1,500 W space heater running 8 hours a day uses 1.5 × 8 = 12 kWh a day. At $0.17 per kWh that costs $2.04 a day, or $61.20 a month if it runs every day. Over a 5-month heating season that is about $306.
What common appliances cost to run
| Appliance | Typical use | Cost per month at $0.17/kWh |
|---|---|---|
| Refrigerator (average draw 60 W) | 24 h/day | about $7.30 |
| Space heater, 1,500 W | 8 h/day | about $61 |
| Window AC, 1,000 W | 8 h/day | about $41 |
| Central AC, 3,500 W | 8 h/day | about $143 |
| TV, 100 W | 5 h/day | about $2.55 |
| Clothes dryer, 3,000 W | 1 h/day | about $15 |
| EV charging, 7.2 kW | 3 h/day | about $110 |
Ways to cut the bill
- Target the big loads. Heating, cooling, water heating and EV charging usually make up most of a home's use. Small electronics rarely matter.
- Use time-of-use rates. If your utility charges less at night, run the dryer, dishwasher and EV charger then.
- Seal and insulate. A tighter home needs less heating and cooling.
- Consider solar. See how many panels would cover your use with the solar panel calculator.
Tracking all household costs? Put your utility bill into the budget calculator.
Frequently asked questions
How much does it cost to run a space heater?
A 1,500 W space heater uses 1.5 kWh per hour. At $0.17 per kWh that is about 26 cents an hour, $2.04 for 8 hours, or roughly $61 a month if used 8 hours every day.
How do I calculate the cost of electricity?
Multiply the appliance's watts by the hours used and divide by 1,000 to get kWh, then multiply by your rate per kWh.
How much electricity does a refrigerator use?
A modern refrigerator uses about 1 to 2 kWh a day, roughly 30 to 60 kWh a month, which costs about $5 to $10 a month at typical US rates.
What is the average cost per kWh in the US?
The average US residential rate is around 16 to 18 cents per kWh, but it ranges from about 11 cents in some states to over 30 cents in California and Hawaii. Check your own bill.
How much does it cost to charge an electric car at home?
Multiply the kWh you add by your rate. Adding 60 kWh at $0.17 per kWh costs about $10.20. Most EVs travel 3 to 4 miles per kWh.
More home project calculators
Last updated October 2026.