Ohm Calculator
Instant electrical conversions & energy cost estimates.
Enter any two values and the rest fill in automatically.
How to Convert Amperes to Kilowatts
Converting current (amperes) to power (kilowatts) requires knowing the voltage of the circuit. Using Ohm's Law and the power equation, first multiply the current in amps by the voltage in volts to get power in watts, then divide by 1,000 to convert to kilowatts. For example, a device drawing 10 amps at 120 volts uses 1,200 watts, or 1.2 kW. Enter any two known values in the calculator above and the remaining figures are worked out instantly.
Frequently Asked Questions
What is Ohm's Law? +
Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points, expressed as V = I × R (Voltage = Current × Resistance). It's the foundation for calculating power, where Watts = Amps × Volts.
How do I convert watts to kilowatts? +
Divide the number of watts by 1,000. For example, 2,500 watts equals 2.5 kilowatts. Kilowatts are typically used to describe larger loads and to measure energy consumption on your utility bill.
How is my electricity bill calculated? +
Utilities charge per kilowatt-hour (kWh). Multiply an appliance's power in kilowatts by the hours it runs to get kWh consumed, then multiply by your electricity rate. The Energy Cost tab above does this automatically for daily, monthly, and yearly estimates.
What is a kilowatt-hour (kWh)? +
A kilowatt-hour is a unit of energy equal to running a 1,000-watt appliance for one hour. It is the standard unit used by energy providers to measure and bill electricity usage.