Kilocalorie to BTU (kcal to BTU)
Result
3.965666831 BTU
Formula
BTU = kcal × 3.965666831
1 kcal = 3.965666831 BTU, and 1 BTU = 0.2521644007 kcal.
The joule is the SI unit of energy. The calorie used here is the thermochemical calorie, exactly 4.184 J; a kilowatt-hour is exactly 3.6 MJ; the BTU is the International Table BTU (1,055.05585262 J).
Worked examples
- 1 kcal × 3.965666831 = 3.9656668 BTU
- 10 kcal × 3.965666831 = 39.656668 BTU
- 100 kcal × 3.965666831 = 396.56668 BTU
Common mistakes
- Food "Calories" (capital C) are kilocalories: a 250 Calorie snack contains 250 kcal, or 1,046 kJ.
- kW is power and kWh is energy: a 2 kW heater running for 3 hours uses 6 kWh.
- The International Table calorie (4.1868 J) is slightly larger than the thermochemical calorie (4.184 J); engineering steam tables use the former.
Kilocalorie to BTU table
| Kilocalorie (kcal) | BTU (BTU) |
|---|---|
| 1 | 3.9656668 |
| 2 | 7.9313337 |
| 5 | 19.828334 |
| 10 | 39.656668 |
| 20 | 79.313337 |
| 50 | 198.28334 |
| 100 | 396.56668 |
| 1,000 | 3,965.6668 |
The units
- Kilocalorie (kcal)
- Kilocalorie (thermochemical): exactly 4,184 J. The "Calorie" on food labels.
- BTU (BTU)
- British thermal unit (International Table): 1,055.05585262 J — roughly the heat to warm one pound of water by 1 °F.
Sources for these factors
- Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST
- The International System of Units (SI Brochure), 9th edition — BIPM
Last reviewed against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy