Btu Btu (15.6°C) Btu (15.8°C, Canada) Btu (15.8°C, ISO) Btu (15°C) Btu (3.9°C) Btu (I.T.) Btu (I.T., pre-1956) Btu (mean) Btu (thermoc.) Calories Calories (15 °C, NBS 1939) Calories (15°C,CIPM, 1950) Calories (20°C) Calories (I.T.) Calories (Kilogram,I.T.) Calories (Kilogram,mean) Calories (Kilogram,thermoc.) Calories (mean) Calories (nutritional) Calories (thermoc.) Electron-volts Ergs Foot-poundals Foot-pounds Joules Kilojoules Kilotons (metric,explosive energy) Kilowatt-hours Megaelectron-volts Megawatt-hours Newton-meters Therm Therms (EC) Therms (UK) Therms (US) → Select type of Btu