Therms to Megajoules Converter
Convert therms to megajoules — one therm is 105.506 MJ. Results update as you type; exact factors shown.
One therm (US) is 105.5056 megajoules — see the exact factor, not a rounded rule of thumb.
How the therms to megajoules converter works
Energy converts through the joule. A thermochemical calorie is exactly 4.184 J, so a food Calorie (kcal) is 4.184 kJ. A kilowatt-hour is exactly 3.6 MJ. A BTU is 1,055.056 J and a US therm is 100,000 BTU.
The US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common energy conversions
| From | To | Units |
|---|---|---|
| 0.1 thm | 10.5506 MJ | therm (US) to megajoules |
| 0.5 thm | 52.7528 MJ | therm (US) to megajoules |
| 1 thm | 105.5056 MJ | therm (US) to megajoules |
| 2 thm | 211.0112 MJ | therm (US) to megajoules |
| 5 thm | 527.5279 MJ | therm (US) to megajoules |
| 10 thm | 1,055.0559 MJ | therm (US) to megajoules |
| 20 thm | 2,110.1117 MJ | therm (US) to megajoules |
| 50 thm | 5,275.2793 MJ | therm (US) to megajoules |
| 100 thm | 10,550.5585 MJ | therm (US) to megajoules |
| 200 thm | 21,101.1171 MJ | therm (US) to megajoules |
| 500 thm | 52,752.7926 MJ | therm (US) to megajoules |
| 1,000 thm | 105,505.5853 MJ | therm (US) to megajoules |
Units in this converter and their exact factors
| Unit | Symbol | One unit in joules |
|---|---|---|
| joule | J | 1 joule |
| kilojoule | kJ | 1,000 joule |
| megajoule | MJ | 1,000,000 joule |
| calorie (thermochemical) | cal | 4.184 joule |
| kilocalorie (food Calorie) | kcal | 4,184 joule |
| watt-hour | Wh | 3,600 joule |
| kilowatt-hour | kWh | 3,600,000 joule |
| British thermal unit | BTU | 1,055.05585262 joule |
| therm (US) | thm | 105,505,585.262 joule |
| foot-pound | ft·lb | 1.3558179483 joule |
FAQFrequently asked questions about energy conversion
How many megajoules in a therm?
105.506 MJ.
What is a therm?
100,000 British thermal units — the traditional gas billing unit.
Which countries bill in therms?
The US mainly; the UK moved to kilowatt-hours. Australia bills gas in megajoules.
What is a therm in kWh?
29.31 kWh.
What is 10 therms?
1,055 MJ — a modest monthly gas bill for a small household.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.