⌕Energy
Turn appliance power, usage, and your electricity rate into a clear cost.
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Electricity cost calculator guide
Electricity cost is the price of the energy an appliance uses, not simply its wattage. This calculator starts with the appliance power rating, converts watts to kilowatts, multiplies by hours of use, and then applies your electricity rate. It shows the same estimate per hour, per day, per 30-day month, and per 365-day year so you can see how a small daily cost adds up. Use the rate from your electricity bill when possible. A label wattage is usually a maximum or nominal draw; refrigerators, air conditioners, heaters with thermostats, and other cycling devices may use less or more than a constant-watt assumption over time. For a quick comparison, enter a realistic average number of hours rather than the number of hours the device is available. This calculator estimates energy usage cost only; fixed charges, taxes, tiered pricing, demand charges, and delivery fees can make the final bill different.
Energy per day (kWh) = watts × hours per day ÷ 1,000. Cost = energy (kWh) × electricity rate. Monthly uses 30 days; annual uses 365 days.
Worked example: a 1,000 W appliance used for 4 hours per day at $0.16 per kWh uses 1,000 × 4 ÷ 1,000 = 4 kWh per day. Daily cost is 4 × $0.16 = $0.64. The 30-day estimate is $0.64 × 30 = $19.20, and the 365-day estimate is $0.64 × 365 = $233.60.
Watts measure power; kilowatt-hours measure energy. Divide watts by 1,000 before multiplying by hours. Your rate must be currency per kWh, not a monthly bill total. The page uses 30 days for a month and 365 days for a year, so calendar billing periods may differ slightly.
Good to know: do not multiply watts directly by dollars per kWh. Convert to kilowatts first. Also avoid using the appliance’s full rated wattage when it cycles, and do not treat this estimate as your entire household bill unless you add every major load and fixed charge.
Results are planning estimates. Check the units, product coverage, carrier rules, or local rates before making a purchase or financial decision.
How it works
Turn appliance power, usage, and your electricity rate into a clear cost. This tool explains the calculation so you can adjust the assumptions to match your situation.
Common questions
Multiply watts by hours used, divide by 1,000 to get kWh, then multiply by your electricity rate per kWh. For daily, monthly, or yearly costs, multiply by the number of days.
At 4 hours per day and $0.16 per kWh, it costs about $0.64 per day, $19.20 per 30-day month, or $233.60 per 365-day year.
Look for the energy charge on your utility bill, usually shown as a price per kWh. If your bill has tiers or time-of-use rates, use the rate that best matches the hours being estimated.
A real bill can include fixed fees, taxes, delivery charges, tiered rates, demand charges, and other appliances. Actual appliance use can also vary because motors and thermostats cycle.
No. Wattage is the rate of power draw. A kilowatt-hour is energy used over time: 1,000 watts running for one hour equals 1 kWh.