BTU to Kilocalories

Convert BTU (BTU) to kilocalories (kcal). Type a value below to see the result update instantly. Reference table and formula included.

Calculator

BTU

⇌

Kilocalories

kcal

1 BTU = 0.252165 kcal

BTU to Kilocalories Conversion Table

Common values, ready to copy:

BTU	kilocalories
1 BTU	0.252165 kcal
2 BTU	0.504331 kcal
5 BTU	1.2608 kcal
10 BTU	2.5217 kcal
25 BTU	6.3041 kcal
50 BTU	12.6083 kcal
100 BTU	25.2165 kcal
1,000 BTU	252.17 kcal

Formula

kilocalories = BTU × 2.52165392e-1

Energy uses the SI joule. Food calories (kcal) are 1,000 small calories: 1 kcal = 4,184 J. 1 kWh = 3.6 MJ = 3,600,000 J. 1 BTU = 1,055.06 J.

About BTU and Kilocalories

BTU (BTU): British Thermal Unit; the energy to raise one pound of water by one degree Fahrenheit; defined as exactly 1,055.06 J. Common uses: US heating and air conditioning (a 24,000 BTU air conditioner cools roughly a 1,500 sq ft room), and US natural gas billing.

Kilocalories (kcal): A thousand small calories, or about 4,184 J; this is what 'calories' means on US food labels. Common uses: Food energy labeling in the US (a 'Calorie' on a US food label is a kilocalorie), nutrition tracking, and exercise energy expenditure.

How the conversion works

Energy uses the SI joule. Food calories (kcal) are 1,000 small calories: 1 kcal = 4,184 J. 1 kWh = 3.6 MJ = 3,600,000 J. 1 BTU = 1,055.06 J.

The exact relationship is kilocalories = BTU × 2.52165392e-1, which the calculator at the top of this page applies in both directions. Type into either field and the other updates immediately.

When this conversion matters

Converting between BTU and kilocalories comes up wherever energy measurements move between systems — from one country's conventions to another's, from a scientific reference to a practical specification, or from one industry's working unit to another's. The calculator and reference table above cover the everyday range; for unusual values you can type any number into either field.