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Energy

Convert BTU to megajoules

1 BTU=0.001055MJ

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

0.0010551

Conversion formula

Forward
megajoules = BTU × 0.001055
Reverse
BTU = megajoules × 947.817

Example: 10 BTU × 0.001055 = 0.01055 MJ.

About both units

From

British Thermal Unit

BTU

The British Thermal Unit equals approximately 1055 joules — the energy to raise 1 pound of water by 1 °F. Used for HVAC, heating, and air-conditioning capacity in the US. A 9000 BTU/h AC is a small room unit.

Real-world: Window AC: 5000–12,000 BTU/h. Central AC: 24,000–60,000 BTU/h. Home furnace: 60,000–100,000 BTU/h.
Read full british thermal unit 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 →

British Thermal Unit to Megajoule conversion table

Common BTU to megajoules values for quick reference.

British Thermal Unit (BTU)Megajoule (MJ)
1 BTU0.001055 MJ
10 BTU0.01055 MJ
100 BTU0.1055 MJ
500 BTU0.5275 MJ
1,000 BTU1.05506 MJ
5,000 BTU5.27528 MJ
10,000 BTU10.5506 MJ
50,000 BTU52.7528 MJ
100,000 BTU105.506 MJ
500,000 BTU527.528 MJ

Tips & common mistakes

Quick tips

  • 1 BTU = 1055.06 J = 0.293 Wh.
  • BTU/h (power) and BTU (energy) are different — don't confuse.
  • Tons of refrigeration: 12,000 BTU/h = 1 ton AC.

Avoid these

  • Confusing BTU and BTU/h — energy vs power.
  • Using kcal when BTU is requested in HVAC specs.
  • Treating all BTUs as exact — definitions vary (IT, thermochemical, etc.).

Frequently asked questions

How many megajoules in a british thermal unit?
One british thermal unit equals 0.001055 megajoules.
How do I convert BTU to megajoules?
Multiply the british thermal unit value by 0.001055 to get the equivalent in megajoules.
What is 100 BTU in megajoules?
100 BTU equals 0.1055 megajoules.
Is a british thermal unit bigger than a megajoule?
No. 1 british thermal unit equals 0.001055 megajoules, so one british thermal unit is smaller.
How to convert BTU 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 British Thermal Unit

BTU → J
1 = 1,055.06 J
BTU → kJ
1 = 1.05506 kJ
BTU → kWh
1 = 0.0002931 kWh
BTU → Wh
1 = 0.2931 Wh
BTU → cal
1 = 252.164 cal
BTU → kcal
1 = 0.2522 kcal
BTU → eV
1 = 6.5851e21 eV
BTU → thm
1 = 1.0000e-5 thm

More to Megajoule

J → MJ
1 = 1.0000e-6 MJ
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
eV → MJ
1 = 1.6022e-25 MJ
thm → MJ
1 = 105.506 MJ

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