Convert BTU to Therms
1 British thermal unit (BTU) equals 0.00001000238767 therms (thm).
1 BTU = 0.00001000238767 thm
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk BTU to therm converter to paste a column from Excel.
How to Convert BTU to Therm
- 1 BTU = 0.00001000238767 thm
- 1 thm = 99976.12898 BTU
- Example: convert 15 BTU to thm: 15 BTU = 15 × 0.00001000238767 thm = 0.0001500358151 thm
Reference conditions. BTU: International Table BTU (BTU_IT), 1055.05585262 J exactly. thm: US therm, 100 000 BTU (59 °F), 105.4804 MJ as given by NIST SP 811. The EC therm is 105.506 MJ.
Formula
thm = BTU × 0.00001000238767221
or thm = BTU ÷ 99976.1289775
Derivation from SI units:
- 1 BTU_IT = 1055.05585262 J (exact)
- 1 thm (US) = 1.054804 × 10⁸ J (NIST SP 811)
- 1 BTU = 1055.05585262 J ÷ 105480400 J per thm = 0.00001000238767221 thm
Both units are defined exactly, so the factor is exact. BTU definition: British thermal unit; Therm definition: therm.
Worked examples
- A reading of 3412 BTU converts to 0.03412814674 thm.
3412 BTU × 0.00001000238767 = 0.03412814674 thm - A value of 24000 BTU is 0.2400573041 thm.
24000 BTU × 0.00001000238767 = 0.2400573041 thm
BTU to Therm conversion table
| BTU | Therms (thm) |
|---|---|
| 1 BTU | 0.00001000238767 thm |
| 100 BTU | 0.001000238767 thm |
| 1000 BTU | 0.01000238767 thm |
| 3412 BTU | 0.03412814674 thm |
| 5000 BTU | 0.05001193836 thm |
| 10000 BTU | 0.1000238767 thm |
| 12000 BTU | 0.1200286521 thm |
| 24000 BTU | 0.2400573041 thm |
| 50000 BTU | 0.5001193836 thm |
| 100000 BTU | 1.000238767 thm |
| 1000000 BTU | 10.00238767 thm |
Where it's used
BTU are used for furnace, boiler and fuel ratings in the US, while therms appear in US and UK natural-gas bills. Both measure energy, work and heat, so the conversion is a fixed factor.
BTU to other energy units
| Conversion | 1 BTU equals |
|---|---|
| BTU to joule | 1055.055853 J |
| BTU to kilojoule | 1.055055853 kJ |
| BTU to megajoule | 0.001055055853 MJ |
| BTU to calorie | 252.1644007 cal |
| BTU to kilocalorie | 0.2521644007 kcal |
| BTU to watt-hour | 0.2930710702 Wh |
| BTU to kilowatt-hour | 0.0002930710702 kWh |
| BTU to therm | 0.00001000238767 thm |
| BTU to electronvolt | 6.585140678 × 10²¹ eV |
| BTU to foot-pound | 778.1692623 ft·lbf |
| BTU to erg | 10550558530 erg |
Frequently asked questions
How many therms are in 1 British thermal unit?
1 BTU = 0.00001000238767 thm.
How do I convert British thermal units to therms?
Multiply the value in BTU by 0.00001000238767, or divide it by 99976.12898. For example, 15 BTU × 0.00001000238767 = 0.0001500358151 thm.
Is the BTU to thm conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "British thermal unit_IT (Btu_IT)".
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "therm (U.S.)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert BTU to Therms. Retrieved October 17, 2026, from https://scientificconverters.com/energy/btu-to-therms/
IEEE
Scientific Converters, "Convert BTU to Therms," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/btu-to-therms/