Convert Calories (cal) to British Thermal Units (BTU)

Enter a value below to convert Calories (cal) to British Thermal Units (BTU).

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Conversion:

1 Calories (cal) = 0.0039656512426 British Thermal Units (BTU)

How to Convert Calories (cal) to British Thermal Units (BTU)

1 cal = 0.0039656512426 btu

1 btu = 252.16539197 cal

Example: convert 15 Calories (cal) to British Thermal Units (BTU):

25 cal = 0.099141281065 btu

Calories (cal) to British Thermal Units (BTU) Conversion Table

Calories (cal)British Thermal Units (BTU)
0.01 cal0.000039656512426 btu
0.1 cal0.00039656512426 btu
1 cal0.0039656512426 btu
2 cal0.0079313024852 btu
3 cal0.011896953728 btu
5 cal0.019828256213 btu
10 cal0.039656512426 btu
20 cal0.079313024852 btu
50 cal0.19828256213 btu
100 cal0.39656512426 btu
1000 cal3.9656512426 btu

Calories (cal)

Definition

A calorie (cal), also known as a small calorie or gram calorie, is defined as the amount of heat energy needed to raise the temperature of one gram of water by one degree Celsius. It equals approximately 4.184 joules.

History

The calorie was first defined by French chemist Nicolas Clément in 1824. It was widely used in chemistry and physiology before the joule became the official SI unit of energy.

Current use

Small calories are used in chemistry and physics for heat measurements. In everyday language, 'calorie' often refers to the kilocalorie (kcal) when discussing food energy.

British Thermal Units (BTU)

Definition

A British Thermal Unit (BTU) is an imperial unit of energy defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. It equals approximately 1,055.06 joules.

History

The BTU originated in the British imperial measurement system in the 19th century. Despite the global shift toward metric units, it remains entrenched in US, UK, and Canadian HVAC and energy industries.

Current use

BTUs are the standard unit for rating heating and cooling equipment (furnaces, air conditioners), measuring natural gas energy content, and comparing fuel efficiencies in North America.