---
title: "British thermal units to Calories — BTU to cal converter"
description: "1 British thermal unit = 252.1644 calories. Conversion table, the exact formula, and a calculator for any value."
url: https://atoneplace.net/convert/btu-to-calories/
site: "At One Place"
---

# British thermal units to calories

**1 British thermal unit in calories: 1 BTU = 252.1644 cal**

cal = BTU × 252.1644007

To convert British thermal units to calories, multiply by 252.1644007. The table below gives the values people look up most often, and the converter works for any number.

## British thermal units to calories table

*Common British thermal unit values converted to calories.*

| British thermal units | Calories |
| --- | --- |
| 1 BTU | 252.1644 |
| 2 BTU | 504.3288 |
| 3 BTU | 756.4932 |
| 4 BTU | 1,008.6576 |
| 5 BTU | 1,260.822 |
| 10 BTU | 2,521.644 |
| 15 BTU | 3,782.466 |
| 20 BTU | 5,043.288 |
| 25 BTU | 6,304.11 |
| 30 BTU | 7,564.932 |
| 40 BTU | 10,086.576 |
| 50 BTU | 12,608.22 |
| 75 BTU | 18,912.33 |
| 100 BTU | 25,216.44 |
| 250 BTU | 63,041.1 |
| 500 BTU | 126,082.2 |
| 1,000 BTU | 252,164.4 |

## How the conversion works

The relationship is cal = BTU × 252.1644007. Both units measure energy, so the conversion is a fixed factor that never changes.

> Calorie: Thermochemical (small) calorie.

## Common questions

### How many calories are in one British thermal unit?

One British thermal unit equals 252.1644 calories. cal = BTU × 252.1644007.

### How do you convert British thermal units to calories?

Use cal = BTU × 252.1644007. So 10 BTU is 2,521.644 cal.

### How many British thermal units are in one calorie?

One calorie equals 0.0039657 British thermal units, which is the reverse of the conversion above.

### Is there more than one kind of calorie?

Thermochemical (small) calorie.

## Related pages

- [Calories to British thermal units](https://atoneplace.net/convert/calories-to-btu/)
- [British thermal units to Joules](https://atoneplace.net/convert/btu-to-joules/)
- [British thermal units to Kilojoules](https://atoneplace.net/convert/btu-to-kilojoules/)
- [British thermal units to Kilocalories](https://atoneplace.net/convert/btu-to-kcal/)
- [British thermal units to Watt-hours](https://atoneplace.net/convert/btu-to-watt-hours/)
- [British thermal units to Kilowatt-hours](https://atoneplace.net/convert/btu-to-kwh/)

## Sources

- Guide for the Use of the International System of Units (SP 811) — NIST (https://www.nist.gov/pml/special-publication-811) [Public domain (US Government)]
- The International System of Units (SI Brochure) — Bureau International des Poids et Mesures (https://www.bipm.org/en/publications/si-brochure)
- Calculated on this page — At One Place (/about/)