Estimate kilowatt-hours from watts, kilowatts, amps, voltage, runtime hours, days, and power factor. This calculator also estimates daily, monthly, yearly energy use and electricity cost.
Power input:
The calculator can use watts, kilowatts, amps, or known kWh.
Runtime:
Power is multiplied by hours and days to estimate total energy use.
Cost estimate:
Total kWh is multiplied by the electric rate to estimate electricity cost.
A kilowatt hour calculator helps estimate how much energy an appliance, circuit, EV charger, shop, heater, or home uses over time.
It can help compare appliances, estimate monthly energy use, estimate EV charging energy, check heater or AC usage, and understand your electric bill.
Your result shows total kWh, daily kWh, monthly kWh, yearly kWh, estimated cost, watts, kilowatts, runtime, electric rate, and appliance row comparisons.
A kilowatt-hour is a measure of energy. It means 1 kilowatt of power used for 1 hour.
Divide watts by 1,000 to get kilowatts, then multiply by hours used. For multiple days, multiply by the number of days.
A 1,500 watt heater is 1.5 kW. If it runs for 8 hours, it uses 12 kWh.
No. kW measures power. kWh measures energy used over time.