British Thermal Units to Kilocalories
Convert British thermal units to kilocalories instantly — one British thermal unit is 0.252164 kilocalories.
| British Thermal Units | Kilocalories |
|---|---|
| 1 BTU | 0.252164 kcal |
| 2 BTU | 0.504329 kcal |
| 3 BTU | 0.756493 kcal |
| 5 BTU | 1.260822 kcal |
| 10 BTU | 2.521644 kcal |
| 25 BTU | 6.30411 kcal |
| 50 BTU | 12.60822 kcal |
| 100 BTU | 25.21644 kcal |
How to use
- Enter a value in the British Thermal Units field.
- The Kilocalories figure appears immediately — no button to press.
- Typing in the Kilocalories field converts back to British Thermal Units the same way.
- Use the reference table for the values that come up most often.
British Thermal Units to Kilocalories formula
The factor from British thermal units to kilocalories is 0.252164401.
kcal = BTU × 0.252164401
Why this factor: the British thermal unit and the kilocalorie are both defined against the joule, so dividing one definition by the other gives 0.252164401 directly. Both definitions are set out in full below.
To go the other way, divide by 0.252164401 — or use the Kilocalories to British Thermal Units converter, which is the same calculation reversed.
Worked example
Given 2000 BTU, multiplying by 0.252164401 yields 504.328801 kcal.
2000 BTU × 0.252164401 = 504.328801 kcal
The converter above does this for any value you type, in either direction.
What is a British thermal unit?
A BTU is the energy needed to raise one pound of water by one degree Fahrenheit.
Definition: The international-table BTU is about 1,055.056 joules.
Where it is used: US heating and air-conditioning capacity ratings, natural gas pricing, and boiler output.
Worth knowing: Air-conditioner ratings quoted as 'BTU' are really BTU per hour — a rate of cooling, not a quantity of energy.
What is a kilocalorie?
A kilocalorie is 1,000 calories, and is what food labeling calls a 'Calorie'.
Definition: Exactly 4,184 joules.
Where it is used: Nutrition and dietary energy in the US and much of the world, and metabolic measurements.
Worth knowing: Written with a capital C ('Calorie') or as 'kcal' on labels. This is the unit meant by everyday talk about counting calories.
British Thermal Units vs Kilocalories
The British thermal unit is a US customary unit while the kilocalorie is a specialized unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many kilocalories are in a British thermal unit?
One British thermal unit equals 0.252164401 kilocalories.
What is the formula to convert British thermal units to kilocalories?
Multiply the number of British thermal units by 0.252164401. To reverse it, divide by 0.252164401 instead.
How do I convert kilocalories back to British thermal units?
Divide by 0.252164401, which is the same as multiplying by 3.96566683.
How many kilocalories are in 10 British thermal units?
10 BTU works out to 2.521644 kcal.
Is there anything to watch out for with British thermal units?
Air-conditioner ratings quoted as 'BTU' are really BTU per hour — a rate of cooling, not a quantity of energy.
How is the British thermal unit defined?
The international-table BTU is about 1,055.056 joules.