Kilojoules to Joules

Convert kJ to J instantly — with a table, common energy values, and a live calculator.

1 kJ equals 1000 J.

Updated June 3, 2026Open the Unit Converter →

Convert any energy

Energy (kJ)

Result (J)1000 J

kJ to J table

kJ	J
1 kJ	1000 J
2 kJ	2000 J
3 kJ	3000 J
5 kJ	5000 J
10 kJ	10000 J
15 kJ	15000 J
20 kJ	20000 J
25 kJ	25000 J
30 kJ	30000 J
40 kJ	40000 J
50 kJ	50000 J
60 kJ	60000 J
75 kJ	75000 J
90 kJ	90000 J
100 kJ	100000 J
120 kJ	120000 J
150 kJ	150000 J
200 kJ	200000 J
250 kJ	250000 J
300 kJ	300000 J
400 kJ	400000 J
500 kJ	500000 J

J to kJ (reverse)

J	kJ
1 J	0.001 kJ
2 J	0.002 kJ
3 J	0.003 kJ
5 J	0.005 kJ
10 J	0.01 kJ
15 J	0.015 kJ
20 J	0.02 kJ
25 J	0.025 kJ
30 J	0.03 kJ
40 J	0.04 kJ
50 J	0.05 kJ
60 J	0.06 kJ
75 J	0.075 kJ
90 J	0.09 kJ
100 J	0.1 kJ
120 J	0.12 kJ
150 J	0.15 kJ
200 J	0.2 kJ
250 J	0.25 kJ
300 J	0.3 kJ
400 J	0.4 kJ
500 J	0.5 kJ

Common energy values

kJ	J
5 kJ	5000 J
10 kJ	10000 J
25 kJ	25000 J
50 kJ	50000 J
75 kJ	75000 J
100 kJ	100000 J
120 kJ	120000 J
150 kJ	150000 J
200 kJ	200000 J
300 kJ	300000 J
400 kJ	400000 J
500 kJ	500000 J

How it scales

1 kWh in other units

The ratio at a glance

Joules, kWh, and calories — the key energy units

Joules (J), kilojoules (kJ), and megajoules (MJ) are the SI units of energy. The kilowatt-hour (kWh) is the unit on your electricity bill and equals 3.6 MJ. With calories there are two sizes that must not be confused: the kilocalorie (kcal) on nutrition labels equals exactly 4184 J (4.184 kJ), while the small calorie (cal) is only 4.184 J — they differ by a factor of 1000. The BTU (British thermal unit) equals 1055.06 J and is used in heating and air-conditioning.

Energy conversions are exact and rest on fixed factors — for more unit pairs, use our energy conversion hub.

Related conversions

Joules to Kilojoules

Kilowatt-hours to Joules

Joules to Kilowatt-hours

Kilocalories to Kilojoules

Kilojoules to Kilocalories

Frequently asked questions

How many J are in 1 kJ?

1 kJ equals 1000 J.

How many J are in 2 kJ?

2 kJ equal 2000 J.

How do I convert kJ to J?

Multiply the energy in kJ by 1000 to get J.

Is the kJ-to-J conversion exact?

Yes. Energy conversions are exact; the values here are only rounded to two decimal places.

What are these energy units used for?

Joules (J), kilojoules (kJ), and megajoules (MJ) are the SI units of energy. The kilowatt-hour (kWh) is the unit on your electricity bill, kilocalories (kcal) appear on food labels, and the BTU (British thermal unit) is used in heating and air-conditioning.

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The unit converter handles length, volume, weight, and more.

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Kilojoules to Joules

Convert kJ to J instantly — with a table, common energy values, and a live calculator.

1 kJ equals 1000 J.

Updated June 3, 2026Open the Unit Converter →

Convert any energy

Energy (kJ)

Result (J)1000 J

kJ to J table

kJ	J
1 kJ	1000 J
2 kJ	2000 J
3 kJ	3000 J
5 kJ	5000 J
10 kJ	10000 J
15 kJ	15000 J
20 kJ	20000 J
25 kJ	25000 J
30 kJ	30000 J
40 kJ	40000 J
50 kJ	50000 J
60 kJ	60000 J
75 kJ	75000 J
90 kJ	90000 J
100 kJ	100000 J
120 kJ	120000 J
150 kJ	150000 J
200 kJ	200000 J
250 kJ	250000 J
300 kJ	300000 J
400 kJ	400000 J
500 kJ	500000 J

J to kJ (reverse)

J	kJ
1 J	0.001 kJ
2 J	0.002 kJ
3 J	0.003 kJ
5 J	0.005 kJ
10 J	0.01 kJ
15 J	0.015 kJ
20 J	0.02 kJ
25 J	0.025 kJ
30 J	0.03 kJ
40 J	0.04 kJ
50 J	0.05 kJ
60 J	0.06 kJ
75 J	0.075 kJ
90 J	0.09 kJ
100 J	0.1 kJ
120 J	0.12 kJ
150 J	0.15 kJ
200 J	0.2 kJ
250 J	0.25 kJ
300 J	0.3 kJ
400 J	0.4 kJ
500 J	0.5 kJ

Common energy values

kJ	J
5 kJ	5000 J
10 kJ	10000 J
25 kJ	25000 J
50 kJ	50000 J
75 kJ	75000 J
100 kJ	100000 J
120 kJ	120000 J
150 kJ	150000 J
200 kJ	200000 J
300 kJ	300000 J
400 kJ	400000 J
500 kJ	500000 J

How it scales

1 kWh in other units

The ratio at a glance

Joules, kWh, and calories — the key energy units

Energy conversions are exact and rest on fixed factors — for more unit pairs, use our energy conversion hub.

Related conversions

Joules to Kilojoules

Kilowatt-hours to Joules

Joules to Kilowatt-hours

Kilocalories to Kilojoules

Kilojoules to Kilocalories

Frequently asked questions

How many J are in 1 kJ?

1 kJ equals 1000 J.

How many J are in 2 kJ?

2 kJ equal 2000 J.

How do I convert kJ to J?

Multiply the energy in kJ by 1000 to get J.

Is the kJ-to-J conversion exact?

Yes. Energy conversions are exact; the values here are only rounded to two decimal places.

What are these energy units used for?

Convert any unit

The unit converter handles length, volume, weight, and more.

Open Unit Converter →

Was this helpful?