Calories (15 °C, NBS 1939) to Btu (I.T.) conversion formula
Btu (I.T.) = Calories (15 °C, NBS 1939) / 252.05614803
Calories (15 °C, NBS 1939) to Btu (I.T.) calculation
Btu (I.T.) = Calories (15 °C, NBS 1939) / 252.05614803
Btu (I.T.) = 1 / 252.05604035378
Btu (I.T.) = 0.00397
Calories (15 °C, NBS 1939)
The 15 °C NBS 1939 calorie is the amount of energy required to raise the temperature of one gram of water by one degree Celsius, from 14.5 °C to 15.5 °C, at standard atmospheric pressure. This specific definition was established by the National Bureau of Standards (NBS) in 1939.
Btu (I.T.)
The British Thermal Unit (International Table) is a unit of energy commonly used in the United States defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit at a constant pressure of one atmosphere.
