Btus to Megajoules
A British Thermal Unit is the energy to raise 1 pound of water by 1°F, used to rate air conditioners and heaters in the US. A megajoule is one million joules, used to measure the energy content of fuels and large-scale energy use. 1 BTU equals ≈0.00105506 MJ, so converting between them is a matter of multiplying by that fixed factor — type any value into the converter below and both sides update instantly as you type.
Both units belong to energy, measured here against energy's base unit (J) — every other energy unit on this site converts through that same reference point, which is why the table below can also be read as a quick cross-check against nearby values.
Formula
MJ = BTU × ≈0.00105506
BTU = MJ × ≈947.817
Worked example: 5 BTU × ≈0.00105506 = ≈0.00527528 MJ.
Conversion table
| BTU (BTU) | Megajoule (MJ) |
|---|---|
| 1 BTU | ≈0.00105506 MJ |
| 2 BTU | ≈0.00211011 MJ |
| 3 BTU | ≈0.00316517 MJ |
| 5 BTU | ≈0.00527528 MJ |
| 10 BTU | ≈0.0105506 MJ |
| 20 BTU | ≈0.0211011 MJ |
| 25 BTU | ≈0.0263764 MJ |
| 50 BTU | ≈0.0527528 MJ |
| 100 BTU | ≈0.105506 MJ |
| 250 BTU | ≈0.263764 MJ |
| 500 BTU | ≈0.527528 MJ |
| 1,000 BTU | ≈1.05506 MJ |
Frequently asked
- How many Megajoules in a btu?
- 1 BTU equals ≈0.00105506 MJ.
- How do I convert BTUs to Megajoules?
- Multiply the value in BTU by ≈0.00105506 to get MJ. The converter above does this instantly as you type.
- Is the conversion exact?
- Yes — BTU and Megajoule are both defined by a fixed conversion factor to energy's base unit (J), so the result shown is exact to the precision displayed, not an approximation.