Therm (EC) ≡ 100000 BTUISO[2] = 105506000 joules ≈ 29.3072 kWh The therm (EC) is often used by engineers in the US. Therm (US) ≡ 100000 BTU59 °F[3] = 105480400 joules ≈ 29.3001111111111 kWh. Therm (UK) ≡ 105505585.257348 joules[4] ≡ 29.3071070159300 kWh