---
title: "Joules to Kilojoules — J to kJ converter"
description: "1 joule = 0.001 kilojoules. Convert joules to kilojoules with a full conversion table, the exact formula, and a calculator for any value."
url: https://atoneplace.net/convert/joules-to-kilojoules/
site: "At One Place"
---

# Joules to kilojoules

**1 joule in kilojoules: 1 J = 0.001 kJ**

kJ = J × 0.001

To convert joules to kilojoules, multiply by 0.001. The table below gives the values people look up most often, and the converter works for any number.

## Joules to kilojoules table

*Common joule values converted to kilojoules.*

| Joules | Kilojoules |
| --- | --- |
| 1 J | 0.001 |
| 2 J | 0.002 |
| 3 J | 0.003 |
| 4 J | 0.004 |
| 5 J | 0.005 |
| 10 J | 0.01 |
| 15 J | 0.015 |
| 20 J | 0.02 |
| 25 J | 0.025 |
| 30 J | 0.03 |
| 40 J | 0.04 |
| 50 J | 0.05 |
| 75 J | 0.075 |
| 100 J | 0.1 |
| 250 J | 0.25 |
| 500 J | 0.5 |
| 1,000 J | 1 |

## How the conversion works

The relationship is kJ = J × 0.001. Both units measure energy, so the conversion is a fixed factor that never changes.

## Common questions

### How many kilojoules are in one joule?

One joule equals 0.001 kilojoules. kJ = J × 0.001.

### How do you convert joules to kilojoules?

Use kJ = J × 0.001. So 10 J is 0.01 kJ.

### How many joules are in one kilojoule?

One kilojoule equals 1,000 joules, which is the reverse of the conversion above.

## Related pages

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