Convert Therms to Foot-pounds
1 therm (thm) equals 77798350.53 foot-pounds (ft·lbf).
1 thm = 77798350.53 ft·lbf
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk therm to foot-pound converter to paste a column from Excel.
How to Convert Therm to Foot-pound
- 1 thm = 77798350.53 ft·lbf
- 1 ft·lbf = 1.285374295 × 10⁻⁸ thm
- Example: convert 15 thm to ft·lbf: 15 thm = 15 × 77798350.53 ft·lbf = 1166975258 ft·lbf
Reference conditions. 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
ft·lbf = thm × 77798350.53063
Derivation from SI units:
- 1 thm (US) = 1.054804 × 10⁸ J (NIST SP 811)
- 1 ft·lbf = 0.3048 m × 4.4482216152605 N = 1.3558179483314 J
- 1 thm = 105480400 J ÷ 1.355817948331 J per ft·lbf = 77798350.53063 ft·lbf
Both units are defined exactly, so the factor is exact. Therm definition: therm; Foot-pound definition: foot-pound.
Worked examples
- A reading of 20 thm converts to 1555967011 ft·lbf.
20 thm × 77798350.53 = 1555967011 ft·lbf - A value of 100 thm is 7779835053 ft·lbf.
100 thm × 77798350.53 = 7779835053 ft·lbf
Therm to Foot-pound conversion table
| Therms (thm) | Foot-pounds (ft·lbf) |
|---|---|
| 1 thm | 77798350.53 ft·lbf |
| 5 thm | 388991752.7 ft·lbf |
| 10 thm | 777983505.3 ft·lbf |
| 20 thm | 1555967011 ft·lbf |
| 50 thm | 3889917527 ft·lbf |
| 75 thm | 5834876290 ft·lbf |
| 100 thm | 7779835053 ft·lbf |
| 500 thm | 38899175270 ft·lbf |
| 1000 thm | 77798350530 ft·lbf |
Where it's used
Therms are used for US and UK natural-gas bills, while foot-pounds appear in muzzle energy of firearms and air rifles. Both measure energy, work and heat, so the conversion is a fixed factor.
Therm to other energy units
| Conversion | 1 thm equals |
|---|---|
| therm to joule | 105480400 J |
| therm to kilojoule | 105480.4 kJ |
| therm to megajoule | 105.4804 MJ |
| therm to calorie | 25210420.65 cal |
| therm to kilocalorie | 25210.42065 kcal |
| therm to watt-hour | 29300.11111 Wh |
| therm to kilowatt-hour | 29.30011111 kWh |
| therm to BTU | 99976.12898 BTU |
| therm to electronvolt | 6.583568738 × 10²⁶ eV |
| therm to foot-pound | 77798350.53 ft·lbf |
| therm to erg | 1.054804 × 10¹⁵ erg |
Frequently asked questions
How many foot-pounds are in 1 therm?
1 thm = 77798350.53 ft·lbf.
How do I convert therms to foot-pounds?
Multiply the value in thm by 77798350.53. For example, 15 thm × 77798350.53 = 1166975258 ft·lbf.
Is the thm to ft·lbf 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, "therm (U.S.)".
- 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, "foot pound-force (ft·lbf)".
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 Therms to Foot-pounds. Retrieved October 17, 2026, from https://scientificconverters.com/energy/therms-to-foot-pounds/
IEEE
Scientific Converters, "Convert Therms to Foot-pounds," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/therms-to-foot-pounds/