What formula does this calculator use?

The calculator uses kWh = (I × V × t) / 1000, where I is current in amperes, V is voltage in volts, and t is time in hours. Multiplying I × V gives power in watts; multiplying by t gives watt-hours; dividing by 1000 converts to kilowatt-hours.

What is a kilowatt-hour?

A kilowatt-hour (kWh) is a unit of energy equal to 1,000 watts consumed for one hour. It is the standard unit used by utility companies to measure and bill electricity consumption.

Can I use this for AC circuits?

This calculator computes apparent energy (VA·h / 1000). For AC circuits with reactive loads, multiply the result by the power factor (PF) to get real energy: kWh = (I × V × t × PF) / 1000. The tool is most accurate for DC or purely resistive AC loads.

How do I convert minutes or seconds to hours?

Divide minutes by 60 to get hours (e.g., 90 minutes = 1.5 hours). Divide seconds by 3600 to get hours (e.g., 3600 seconds = 1 hour).

What is the difference between kWh and kW?

kW (kilowatts) measures power — the rate of energy use at a single moment. kWh (kilowatt-hours) measures energy — the total amount of electricity consumed over time. kWh = kW × hours.

How many kWh does a 10-amp, 120-volt device use in 5 hours?

kWh = (10 × 120 × 5) / 1000 = 6000 / 1000 = 6 kWh.

Amps to Kilowatt Hours Calculator

Enter current (A), voltage (V), and time (hours) to calculate electrical energy consumption in kilowatt-hours (kWh).

Input Values

Current (A)

Voltage (V)

Time (hours) e.g. 1.5 for 90 min

Result

Enter values and press Calculate

Formula

Energy Formula

kWh = (A × V × h) / 1000

Intermediate — Power

W = A × V

Intermediate — Watt-Hours

Wh = W × h

Result copied!

Summary

This calculator converts electrical current in amperes (A) combined with voltage in volts (V) and time in hours (h) into energy measured in kilowatt-hours (kWh). Kilowatt-hours are the standard unit used on electricity bills and for battery capacity. The formula is straightforward: kWh = (I × V × t) / 1000, where dividing by 1000 converts watt-hours to kilowatt-hours.

How it works

Enter the current draw in amperes (A).
Enter the supply voltage in volts (V).
Enter the duration in hours (h).
Press Calculate to see the energy result in kilowatt-hours (kWh).
The breakdown panel shows watts, watt-hours, and the applied formula.
Press Reset to clear all fields and start a new calculation.

Use cases

Estimate electricity consumption of appliances such as air conditioners, heaters, or refrigerators.
Calculate how much energy a battery delivers based on its discharge current and voltage.
Verify electricity meter readings by computing expected kWh from circuit measurements.
Size solar panels and battery banks by modeling load energy over time.
Determine EV charging energy from charging current, voltage, and session duration.
Calculate generator fuel consumption by converting load current to energy drawn.
Plan industrial motor running costs by converting rated current to daily kWh usage.

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu