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Energy

Convert joules to megajoules

1 J=1.0000e-6MJ

Use the converter below to change any joules value into megajoules instantly — with formula, conversion table, and real-world examples.

1.0000e-6

Conversion formula

Forward
megajoules = joules × 1.0000e-6
Reverse
joules = megajoules × 1,000,000

Example: 10 J × 1.0000e-6 = 1.0000e-5 MJ.

About both units

From

Joule

J

The joule is the SI unit of energy, work and heat. Defined as one newton-metre or one watt-second. Named after James Prescott Joule who demonstrated the mechanical equivalent of heat. Lifting a 100 g apple 1 metre requires about 1 J.

Real-world: Lifting a 100 g apple 1 m: ≈ 1 J. 100 kcal snack: 418,400 J. Hand grenade: ~650 kJ.
Read full joule reference →
To

Megajoule

MJ

The megajoule equals 1,000,000 joules. Used for fuel energy content, large-scale mechanical work and in some European natural-gas billing. A litre of petrol contains about 34 MJ of energy.

Real-world: 1 L petrol: ~34 MJ. 1 L diesel: ~38 MJ. Tesla Model 3 full charge: ~270 MJ.
Read full megajoule reference →

Joule to Megajoule conversion table

Common joules to megajoules values for quick reference.

Joule (J)Megajoule (MJ)
1 J1.0000e-6 MJ
10 J1.0000e-5 MJ
100 J0.0001 MJ
500 J0.0005 MJ
1,000 J0.001 MJ
5,000 J0.005 MJ
10,000 J0.01 MJ
50,000 J0.05 MJ
100,000 J0.1 MJ
500,000 J0.5 MJ

Tips & common mistakes

Quick tips

  • 1 J = 1 N·m = 1 W·s.
  • 1 kWh = 3,600,000 J (3.6 MJ).
  • For nutrition 1 kcal = 4.184 kJ.

Avoid these

  • Confusing joule (energy) with newton (force).
  • Mixing joule with watt — watt is joule per second.
  • Using kJ when labels call for kcal on US nutrition.

Frequently asked questions

How many megajoules in a joule?
One joule equals 1.0000e-6 megajoules.
How do I convert joules to megajoules?
Multiply the joule value by 1.0000e-6 to get the equivalent in megajoules.
What is 100 joules in megajoules?
100 joules equals 0.0001 megajoules.
Is a joule bigger than a megajoule?
No. 1 joule equals 1.0000e-6 megajoules, so one joule is smaller.
How to convert joules to megajoules without a calculator?
Multiply by 0 for a quick estimate; use a calculator for precise results.

Related energy conversions

📊 See full comparison matrix →

More from Joule

J → kJ
1 = 0.001 kJ
J → kWh
1 = 2.7778e-7 kWh
J → Wh
1 = 0.0002778 Wh
J → cal
1 = 0.239 cal
J → kcal
1 = 0.000239 kcal
J → BTU
1 = 0.0009478 BTU
J → eV
1 = 6.2415e18 eV
J → thm
1 = 9.4782e-9 thm

More to Megajoule

kJ → MJ
1 = 0.001 MJ
kWh → MJ
1 = 3.6 MJ
Wh → MJ
1 = 0.0036 MJ
cal → MJ
1 = 4.1840e-6 MJ
kcal → MJ
1 = 0.004184 MJ
BTU → MJ
1 = 0.001055 MJ
eV → MJ
1 = 1.6022e-25 MJ
thm → MJ
1 = 105.506 MJ

Conversions in other categories

WeightKilogram → PoundLengthKilometer → MileTemperatureCelsius → FahrenheitVolumeLiter → US GallonAreaSquare Meter → Square FootSpeedKilometer per Hour → Mile per HourPressureBar → Pound per Square InchPowerKilowatt → Mechanical Horsepower