Convert kJ to joules

Enter the number of kilojoules that you want to convert to joules.

1 kJ (kilojoules) = 1000 J (joules)

How to Convert Kilojoules to Joules

The kilojoule and joule are both units of energy. By definition, 1 kilojoule equals exactly 1000 joules. This means to convert kilojoules to joules, you multiply by 1000.

Formula

joules = kilojoules × 1000

Step-by-Step Example

Convert 5 kJ to joules:

1
Convert 5 kJ to joules

We need to convert kilojoules to joules

2
Apply the formula

Since 1 kJ = 1000 J, multiply by 1000

5 × 1000 = 5000

Answer

5 kJ = 5000 J

Kilojoule to Joule Conversion Table

Quick reference table for common kilojoule to joule conversions. Click any value for detailed calculation.

Kilojoules (kJ) Joules (J)
0.1 kJ 100 J
0.5 kJ 500 J
1 kJ 1000 J
2 kJ 2000 J
5 kJ 5000 J
10 kJ 10000 J
25 kJ 25000 J
50 kJ 50000 J
100 kJ 100000 J

About These Units

Kilojoule (kJ)

A kilojoule (kJ) equals 1,000 joules or approximately 239 calories. Kilojoules measure food energy on nutrition labels in Australia, Europe, and many countries. An average adult needs 8,400-10,000 kJ daily. One kJ equals approximately 0.239 kcal.

Joule (J)

The joule (J) is the SI unit of energy equal to one watt-second or one newton-meter. Joules measure work, heat, and electrical energy. One joule equals approximately 0.239 calories. Lifting a 100g apple one meter requires about 1 joule. Named after physicist James Prescott Joule.

Frequently Asked Questions

How do I convert kilojoules to joules?

To convert kilojoules to joules, multiply the value by 1000. For example, 10 kJ = 10000 J.

How many joules are in 1 kilojoule?

1 kilojoule equals 1000 joules.

What is the formula for kilojoules to joules?

The formula is: J = kJ × 1000.