Calories (15 °C, NBS 1939) conversion

Use the search box to find your required metric converter

Calories (15 °C, NBS 1939)


  • cal(NBS)

Unit of:

  • Energy and power

Worldwide use:

  • As part of the metric system but not an SI unit, calories still have widespread use but are being superceded by the Joule


The National Bureau of Standards (NBS, now known as The National Institute of Standards and Technology) defined the cal15 as being the ammount of energy needed to warm 1g of water from 14.5°C to 15.5°C


The calorie was defined in 1824 by Nicolas Clément as a unit of heat. It is a metric unit that has been superceeded in the SI units by the Joule

Usage context:

The calorie is widely used for measurements in chemistry


  • There are 1,000 gram calories in a Kilgram Calorie