Convert Joules to Therms
1 joule (J) equals 9.48043428 × 10⁻⁹ therms (thm).
1 J = 9.48043428e-9 thm
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk joule to therm converter to paste a column from Excel.
How to Convert Joule to Therm
- 1 J = 9.48043428 × 10⁻⁹ thm
- 1 thm = 105480400 J
- Example: convert 15 J to thm: 15 J = 15 × 9.48043428 × 10⁻⁹ thm = 1.422065142 × 10⁻⁷ thm
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
thm = J ÷ 105480400
Derivation from SI units:
- 1 J = 1 N·m = 1 W·s = 1 kg·m²·s⁻²
- 1 thm (US) = 1.054804 × 10⁸ J (NIST SP 811)
Both units are defined exactly, so the factor is exact. Joule definition: joule; Therm definition: therm.
Worked examples
- A reading of 250 J converts to 0.00000237010857 thm.
250 J × 9.48043428 × 10⁻⁹ = 0.00000237010857 thm - A value of 10000 J is 0.0000948043428 thm.
10000 J × 9.48043428 × 10⁻⁹ = 0.0000948043428 thm
Joule to Therm conversion table
| Joules (J) | Therms (thm) |
|---|---|
| 1 J | 9.48043428 × 10⁻⁹ thm |
| 10 J | 9.48043428 × 10⁻⁸ thm |
| 100 J | 9.48043428 × 10⁻⁷ thm |
| 250 J | 0.00000237010857 thm |
| 500 J | 0.00000474021714 thm |
| 1000 J | 0.00000948043428 thm |
| 4184 J | 0.00003966613703 thm |
| 10000 J | 0.0000948043428 thm |
| 100000 J | 0.000948043428 thm |
| 1000000 J | 0.00948043428 thm |
| 3600000 J | 0.03412956341 thm |
Where it's used
Joules are used for physics and engineering energy balances, while therms appear in US and UK natural-gas bills. Both measure energy, work and heat, so the conversion is a fixed factor.
Joule to other energy units
| Conversion | 1 J equals |
|---|---|
| joule to kilojoule | 0.001 kJ |
| joule to megajoule | 0.000001 MJ |
| joule to calorie | 0.2390057361 cal |
| joule to kilocalorie | 0.0002390057361 kcal |
| joule to watt-hour | 0.0002777777778 Wh |
| joule to kilowatt-hour | 2.777777778 × 10⁻⁷ kWh |
| joule to BTU | 0.0009478171203 BTU |
| joule to therm | 9.48043428 × 10⁻⁹ thm |
| joule to electronvolt | 6.241509074 × 10¹⁸ eV |
| joule to foot-pound | 0.7375621493 ft·lbf |
| joule to erg | 10000000 erg |
Frequently asked questions
How many therms are in 1 joule?
1 J = 9.48043428 × 10⁻⁹ thm.
How do I convert joules to therms?
Multiply the value in J by 9.48043428 × 10⁻⁹, or divide it by 105480400. For example, 15 J × 9.48043428 × 10⁻⁹ = 1.422065142 × 10⁻⁷ thm.
Is the J 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
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4, coherent derived units with special names.
- 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 Joules to Therms. Retrieved October 17, 2026, from https://scientificconverters.com/energy/joules-to-therms/
IEEE
Scientific Converters, "Convert Joules to Therms," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/joules-to-therms/