Electricity Cost Calculator – kWh and Cost per Appliance
Find out how much your appliances cost to run. Add devices with their watts and daily hours to see kWh and cost per day, month and year.
Cost = watts × hours used ÷ 1,000 × price per kWh. A 1,500 W heater used 4 hours a day uses 6 kWh a day; at $0.17 per kWh that is about $1.02 a day, or roughly $31 a month.
How to use Electricity Cost Calculator
- Enter the price you pay per kWh — you will find it on your electricity bill.
- Pick appliances from the list or add your own row with the power in watts.
- Set how many hours a day each one runs and how many you have.
- Read the cost per month, day and year, plus the kWh used. With two or more rows you also see which device costs the most.
From watts to kWh to money
Electricity is billed in kilowatt-hours (kWh). One kWh is 1,000 watts running for one hour. To find the energy an appliance uses, multiply its power by the hours it runs and divide by 1,000:
kWh per day = watts × hours per day ÷ 1,000
Then multiply by your price per kWh. The calculator does this for every row and adds them up, using an average month of 30.4 days.
Typical power use of home appliances
| Appliance | Typical watts | kWh per month* |
|---|---|---|
| Refrigerator | 100–200 (average) | 70–145 |
| Air conditioner | 1,000–3,500 | 180–630 (6 h/day) |
| Electric space heater | 1,500 | 180 (4 h/day) |
| LED TV | 50–150 | 6–18 (4 h/day) |
| Laptop | 30–90 | 5–16 (6 h/day) |
| Wi-Fi router | 6–15 | 4–11 |
*Approximate. A fridge cycles on and off, so its average power is much lower than its peak.
Where to find the wattage
Look for a label on the back or bottom of the device, the power adapter or the manual. If it only shows amps, multiply amps by your mains voltage (120 V in North America, 230 V in most other countries). For the most accurate figure, a plug-in energy meter measures the real consumption.
What is a normal price per kWh?
Prices depend on the country, the supplier and the time of day. In the United States the average home price has been around 16–17 cents per kWh in recent years, while many European countries pay 25–40 euro cents. Use the figure on your own bill — including taxes and fees — for a realistic result.
Ways to cut the bill
Heating, cooling, water heating and dryers usually use the most. Lowering the thermostat by 1 °C, washing at 30 °C and switching standby devices off at the plug add up over a year. To compare with driving costs, see the Fuel Cost Calculator; to see what savings could grow into, try the Compound Interest Calculator.
You may also find these free tools useful: Compound Interest Calculator, Fuel Cost Calculator and Loan Calculator.
Frequently asked questions
How do I calculate electricity cost?
Multiply the power in watts by the hours used, divide by 1,000 to get kWh, then multiply by your price per kWh.
How many kWh does a house use per month?
It varies a lot by climate and home size. A typical US home uses around 850–900 kWh a month; homes in Europe often use 250–400 kWh.
How do I convert watts to kWh?
kWh = watts × hours ÷ 1,000. For example, a 60 W laptop running for 10 hours uses 0.6 kWh.
Does an appliance on standby use electricity?
Yes, usually 0.5–5 W each. That is small per device but can add up to several dollars a month across a home.
Why is my bill higher than the calculator shows?
Bills include fixed charges, taxes and appliances you may have missed, and real usage hours are often longer than we estimate.
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