⚡ MJ to kJ — Megajoule to Kilojoule Converter

Convert energy units — joules, kilowatt-hours, calories, BTU, electron volts and more.

1 unit =
From
To
Formula 1 MJ = 1000 kJ
UnitNameValue
0.001 MJ1 kJ
0.01 MJ10 kJ
0.1 MJ100 kJ
1 MJ1000 kJ
5 MJ5000 kJ
10 MJ10000 kJ
50 MJ50000 kJ
100 MJ100000 kJ
1000 MJ1e+06 kJ

Quick Answer

Formula: Kilojoule = Megajoule × 1000

Multiply any megajoule value by 1000 to get kilojoule.

Reverse: Megajoule = Kilojoule × 0.001

Worked Examples

1 MJ
1 MJ × 1000 = 1000 kJ
Single unit reference.
10 MJ
10 MJ × 1000 = 10,000 kJ
10 units — small-scale energy reference.
100 MJ
100 MJ × 1000 = 100,000 kJ
100 units — medium-scale energy.
1000 MJ
1000 MJ × 1000 = 1e+06 kJ
1,000 units — large-scale energy reference.

Megajoule to Kilojoule Conversion Table

Common megajoule values — factor: 1 MJ = 1000 kJ

Megajoule (MJ)Kilojoule (kJ)Context
0.001 MJ1 kJ1 kJ
0.01 MJ10 kJ10 kJ
0.1 MJ100 kJ100 kJ
1 MJ1,000 kJ1 MJ
3.6 MJ3,600 kJ1 kWh
10 MJ1e+04 kJ10 kWh
34 MJ3.4e+04 kJ1L petrol
100 MJ1e+05 kJ~28 kWh
360 MJ3.6e+05 kJ100 kWh
1,000 MJ1e+06 kJ~278 kWh
4,600 MJ4.6e+06 kJ1 tonne TNT
1e+04 MJ1e+07 kJ~2.8 MWh
1e+05 MJ1e+08 kJ~28 MWh
1e+06 MJ1.000e+09 kJ~278 MWh
1.000e+09 MJ1.000e+12 kJ~278 GWh

Mental Math Tricks

× 1000 exactly

MJ × 1,000 = kJ. Exact.

1 MJ = 1,000 kJ

Simple mega prefix.

Reverse

kJ ÷ 1,000 = MJ.

Who Uses This Conversion?

Petroleum Engineer

Measures fuel energy content — 1 liter of petrol ≈ 34 MJ.

EV Engineer

Compares battery pack energy in MJ and kWh for range calculations.

Explosives Engineer

Quantifies explosive yield — 1 kg TNT ≈ 4.6 MJ.

Renewable Energy Engineer

Calculates daily/annual energy yield of solar and wind in MJ.

Transport Economist

Compares fuel energy costs across transport modes in MJ/km.

Building Physicist

Models annual heating and cooling energy demand in MJ.

Frequently Asked Questions

About Megajoule and Kilojoule

Megajoule (MJ)

The megajoule (MJ) equals 1,000,000 joules and is used for large-scale energy measurements in engineering, transportation, and industrial processes.

One liter of petrol contains about 34 MJ of chemical energy. A bolt of lightning releases about 1-5 MJ. An adult's daily food intake is roughly 8-10 MJ. Electric vehicle batteries are typically rated at 40-100 MJ (11-28 kWh).

Interesting fact: The kinetic energy of a 1,000 kg car traveling at 100 km/h is about 0.385 MJ. TNT explosive releases about 4.6 MJ per kilogram when detonated.

Kilojoule (kJ)

The kilojoule (kJ) equals 1,000 joules and is the practical energy unit for food, chemistry, and heating applications in metric countries. Food energy labels in Australia, Europe, and most of the world use kilojoules.

A dietary calorie (kcal) equals 4.184 kJ. A can of soda contains about 600 kJ. The specific heat of water (4.184 kJ/kg·°C) means heating 1 liter of water by 1°C requires 4.184 kJ.

Interesting fact: An average adult needs about 8,000-10,000 kJ (2,000-2,400 kcal) per day. Running a marathon burns approximately 12,500 kJ.

About Megajoule to Kilojoule Conversion

Converting megajoule to kilojoule is common across energy, nutrition, engineering, and science. Different sectors use different energy units — joules in physics, kcal in nutrition, kWh in electricity, and BTU in HVAC — making accurate conversion essential for cross-disciplinary work and international comparisons.

Quick reference: 5 MJ = 5000 kJ and 10 MJ = 10,000 kJ. Reverse: 1 kJ = 0.001 MJ. Exact factor: 1 MJ = 1000 kJ.

All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.