Convert Joules to Therms
Convert Joules (J) to Therms (thm) instantly and accurately.
Conversion Formula
thm = J × 9.478171203e-9
About Joules
The joule (J) is the SI unit of energy, defined as one newton acting through one metre (1 J = 1 N·m = 1 kg·m²/s²). Named after James Prescott Joule, whose 1840s paddle-wheel experiments established the mechanical equivalent of heat (~4.15 J = 1 calorie). One joule is modest: it lifts a 100 g apple by 1 m, heats 0.239 mL of water by 1°C, or powers a 1 W LED for 1 second. Daily adult resting metabolism is ~6-9 MJ. 1 J = 1 W·s = 0.23901 cal = 9.4782 × 10⁻⁴ BTU = 2.7778 × 10⁻⁷ kWh.
About Therms
A therm is the US natural gas billing unit equal to exactly 100,000 BTU = 105,505,585.262 J ≈ 105.5 MJ. One CCF of average US pipeline gas contains ~1.02 therms. The EIA publishes residential gas prices in $/therm; spot prices at Henry Hub are in $/MMBTU (1 MMBTU = 10 therms). US households average 500-700 therms/year for space heating, water heating, and cooking. A 15 kW domestic boiler running 2 hours delivers ~1 therm of useful heat. 1 therm = 100,000 BTU = 105.506 MJ = 29.307 kWh = 25,200 kcal.
Quick Reference Table
| Joules (J) | Therms (thm) |
|---|---|
| 1 J | 9.478 × 10-9 thm |
| 2 J | 1.896 × 10-8 thm |
| 5 J | 4.739 × 10-8 thm |
| 10 J | 9.478 × 10-8 thm |
| 25 J | 2.37 × 10-7 thm |
| 50 J | 4.739 × 10-7 thm |
| 100 J | 9.478 × 10-7 thm |