---
title: "Watt-hours to Kilojoules — Wh to kJ converter"
description: "1 watt-hour = 3.6 kilojoules. Convert watt-hours to kilojoules with a full conversion table, the exact formula, and a calculator for any value."
url: https://atoneplace.net/convert/watt-hours-to-kilojoules/
site: "At One Place"
---

# Watt-hours to kilojoules

**1 watt-hour in kilojoules: 1 Wh = 3.6 kJ**

kJ = Wh × 18/5

To convert watt-hours to kilojoules, multiply by 3.6. The table below gives the values people look up most often, and the converter works for any number.

## Watt-hours to kilojoules table

*Common watt-hour values converted to kilojoules.*

| Watt-hours | Kilojoules |
| --- | --- |
| 1 Wh | 3.6 |
| 2 Wh | 7.2 |
| 3 Wh | 10.8 |
| 4 Wh | 14.4 |
| 5 Wh | 18 |
| 10 Wh | 36 |
| 15 Wh | 54 |
| 20 Wh | 72 |
| 25 Wh | 90 |
| 30 Wh | 108 |
| 40 Wh | 144 |
| 50 Wh | 180 |
| 75 Wh | 270 |
| 100 Wh | 360 |
| 250 Wh | 900 |
| 500 Wh | 1,800 |
| 1,000 Wh | 3,600 |

## How the conversion works

The relationship is kJ = Wh × 18/5. Both units measure energy, so the conversion is a fixed factor that never changes.

## Common questions

### How many kilojoules are in one watt-hour?

One watt-hour equals 3.6 kilojoules. kJ = Wh × 18/5.

### How do you convert watt-hours to kilojoules?

Use kJ = Wh × 18/5. So 10 Wh is 36 kJ.

### How many watt-hours are in one kilojoule?

One kilojoule equals 0.27778 watt-hours, which is the reverse of the conversion above.

## Related pages

- [Kilojoules to Watt-hours](https://atoneplace.net/convert/kilojoules-to-watt-hours/)
- [Watt-hours to Joules](https://atoneplace.net/convert/watt-hours-to-joules/)
- [Watt-hours to Kilocalories](https://atoneplace.net/convert/watt-hours-to-kcal/)
- [Watt-hours to Kilowatt-hours](https://atoneplace.net/convert/watt-hours-to-kwh/)
- [Watt-hours to British thermal units](https://atoneplace.net/convert/watt-hours-to-btu/)

## Sources

- Guide for the Use of the International System of Units (SP 811) — NIST (https://www.nist.gov/pml/special-publication-811) [Public domain (US Government)]
- The International System of Units (SI Brochure) — Bureau International des Poids et Mesures (https://www.bipm.org/en/publications/si-brochure)
- Calculated on this page — At One Place (/about/)