Energy is the capacity to perform work. It exists in various forms, such as kinetic, potential, thermal, etc. It is measured in joules (J).
1 kcal = 3.966 BTU 
1 BTU = 0.252 kcal 
उदाहरण: 
कन्वर्ट 15 Kilocalorie से British Thermal Unit:
15 kcal = 59.485 BTU 
| Kilocalorie | British Thermal Unit | 
|---|---|
| 0.01 kcal | 0.04 BTU | 
| 0.1 kcal | 0.397 BTU | 
| 1 kcal | 3.966 BTU | 
| 2 kcal | 7.931 BTU | 
| 3 kcal | 11.897 BTU | 
| 5 kcal | 19.828 BTU | 
| 10 kcal | 39.657 BTU | 
| 20 kcal | 79.313 BTU | 
| 30 kcal | 118.97 BTU | 
| 40 kcal | 158.626 BTU | 
| 50 kcal | 198.283 BTU | 
| 60 kcal | 237.939 BTU | 
| 70 kcal | 277.596 BTU | 
| 80 kcal | 317.252 BTU | 
| 90 kcal | 356.909 BTU | 
| 100 kcal | 396.565 BTU | 
| 250 kcal | 991.413 BTU | 
| 500 kcal | 1,982.826 BTU | 
| 750 kcal | 2,974.238 BTU | 
| 1000 kcal | 3,965.651 BTU | 
| 10000 kcal | 39,656.512 BTU | 
| 100000 kcal | 396,565.124 BTU |