How many kilojoules are in a kilowatt-hour?

One kilowatt-hour (kWh) equals exactly 3,600 kilojoules (kJ). This follows from 1 kWh = 1,000 W × 3,600 s = 3,600,000 J = 3,600 kJ.

How do I convert kilojoules to kilowatt-hours?

Divide the number of kilojoules by 3,600. For example, 7,200 kJ ÷ 3,600 = 2 kWh.

How do I convert kilowatt-hours to kilojoules?

Multiply the number of kilowatt-hours by 3,600. For example, 0.5 kWh × 3,600 = 1,800 kJ.

Is the kJ to kWh conversion exact?

Yes. By SI definition, 1 kWh = 3,600 kJ exactly. No approximation is involved.

Why do food labels use kilojoules instead of kilowatt-hours?

Kilojoules are the SI unit for food energy in most countries. A typical daily diet is around 8,700 kJ (about 2.42 kWh). Kilowatt-hours are used in electrical contexts rather than nutrition.

How does this differ from the joule-to-kWh conversion?

1 kWh = 3,600,000 J but only 3,600 kJ — so the divisor is 1,000 times smaller. Using kJ instead of J avoids the large numbers common in joule-level calculations.

Kilojoules to Kilowatt Hours Converter

Name: Kilojoules to Kilowatt Hours Converter
Availability: InStock
Author: Nham Vu

Convert kilojoules to kilowatt-hours (or kWh to kJ) instantly — 1 kWh = 3,600 kJ exactly.

Energy Converter

Value in kilojoules (kJ)

Kilowatt-hours (kWh)

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kWh = kJ ÷ 3,600

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Quick Reference Table

Kilojoules (kJ)	kWh	Context

kWh	Kilojoules (kJ)	Context

1 kWh = 3,600 kJ (exact) • 1 kJ = 1,000 J • 1 kJ ≈ 2.7778×10^-4 kWh

Summary

Convert kilojoules to kilowatt-hours (or kWh to kJ) instantly — 1 kWh = 3,600 kJ exactly.

How it works

Select a conversion direction: kJ to kWh, or kWh to kJ.
Enter your energy value in the input field.
The result appears instantly with the formula shown below.
Click Swap to reverse direction without clearing your value.
Use the reference table to look up common conversions at a glance.

Use cases

Convert food energy (kJ from nutrition labels) into the kWh scale used for electricity.
Estimate battery capacity: convert kJ ratings from datasheets into kWh.
Cross-check solar panel output figures given in kJ against kWh meter readings.
Understand how many kJ are stored in a 1 kWh home battery pack.
Verify unit conversions in physics or engineering homework.
Compare energy content of fuels expressed in kJ per kg against kWh equivalents.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu