Megajoule is 1000000 joule units.
Megajoules to BTU Converter — MJ to BTU
Convert Megajoule (MJ) to BTU (BTU) using the exact conversion factor (1 megajoule = 947.8171203 btu). See the formula, worked examples, conversion table, history, and common uses.
Megajoules to BTU converter
Converter
Energy Converter
Convert joules, calories, kilowatt-hours, BTU, electronvolts, therms, and mechanical work units.
Context values
Some unit families need one extra value for a physically accurate result.
British thermal unit.
Result = input x 1e+6 / 1055.055853.
Energy uses the joule as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Megajoules to BTU
Megajoule and BTU both measure energy, and the conversion is especially useful for comparing nutrition labels (kilocalories) against scientific energy figures (joules). Specifically: Megajoule is 1000000 joule units, and british thermal unit.
Formula
btu = megajoules × 947.817120313
This factor comes from each unit's defined relationship to the category's base unit: 1 megajoule equals 1000000 base units, and 1 btu equals 1055.05585262 base units, so dividing one by the other gives the direct megajoule-to-btu factor of 947.817120313.
Simple example
1 MJ × 947.8171203 = 947.8171203 BTU
1 megajoule = 947.8171203 btu.
Real-world example
100 MJ × 947.8171203 = 94,781.71203 BTU
100 megajoules = 94,781.71203 btu.
Conversion table
| Megajoule (MJ) | BTU (BTU) |
|---|---|
| 1 MJ | 947.8171203 BTU |
| 10 MJ | 9,478.171203 BTU |
| 100 MJ | 94,781.71203 BTU |
| 500 MJ | 473,908.5602 BTU |
| 1,000 MJ | 947,817.1203 BTU |
| 2,000 MJ | 1,895,634.241 BTU |
Reverse conversion: BTU to Megajoule
947.8171203 BTU × 0.001055055853 = 1 MJ
947.8171203 btu = 1 megajoules.
megajoules = btu × 0.00105505585262
For a page dedicated to this direction, see BTU to Megajoule.
Understanding the Megajoule (MJ)
Megajoule is 1000000 joule units.
Understanding the BTU
BTU (BTU) measures energy. A British thermal unit is defined as exactly 1,055.05585262 joules (the International Table BTU). It is classified as a US customary unit.
Where it's used: United States (HVAC, heating, and appliance energy ratings)
Uses of the BTU today
- Air conditioner and furnace capacity ratings in the US
- Water heater and appliance energy specifications
- US energy industry (natural gas is often billed via BTU content)
History of the BTU
The BTU originated in 19th-century steam engineering as the heat needed to raise one pound of water by one degree Fahrenheit, paralleling the calorie's metric definition. Several slightly different BTU values existed historically before the 'International Table' BTU was standardized at exactly 1,055.05585262 joules.
Historical origin. BTU was not the invention of a single named person; it developed through the process described above.
BTU — sources
- NIST Special Publication 811 — Documents the International Table BTU's exact joule equivalence.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many btu are in 1 megajoule?
1 megajoule equals 947.8171203 btu, using the exact defined conversion factor rather than an estimate.
How do I convert megajoule to btu?
Multiply the megajoule value by 947.8171203. The converter above does this instantly to whatever precision you set.
How do I convert btu back to megajoule?
Use the reverse factor: 1 btu equals 0.0010550559 megajoules. You can also use the swap control in the converter above to flip the direction instantly.
What is a megajoule?
Megajoule (MJ) is a unit of energy.
What is a btu?
BTU (BTU) measures energy. A British thermal unit is defined as exactly 1,055.05585262 joules (the International Table BTU). It is classified as a US customary unit.
Is the megajoule to btu conversion exact?
Yes. A British thermal unit is defined as exactly 1,055.05585262 joules (the International Table BTU). That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.