能量是执行工作的能力。它以各种形式存在，例如动力学，电势，热等。在焦耳（J）中测量。
1 J = 0.738 ft·lb
1 ft·lb = 1.356 J
例子:
将15 焦耳转换为脚：
15 J = 11.063 ft·lb
| 焦耳 | 脚 |
|---|---|
| 0.01 J | 0.007 ft·lb |
| 0.1 J | 0.074 ft·lb |
| 1 J | 0.738 ft·lb |
| 2 J | 1.475 ft·lb |
| 3 J | 2.213 ft·lb |
| 5 J | 3.688 ft·lb |
| 10 J | 7.376 ft·lb |
| 20 J | 14.751 ft·lb |
| 30 J | 22.127 ft·lb |
| 40 J | 29.502 ft·lb |
| 50 J | 36.878 ft·lb |
| 60 J | 44.254 ft·lb |
| 70 J | 51.629 ft·lb |
| 80 J | 59.005 ft·lb |
| 90 J | 66.38 ft·lb |
| 100 J | 73.756 ft·lb |
| 250 J | 184.39 ft·lb |
| 500 J | 368.781 ft·lb |
| 750 J | 553.171 ft·lb |
| 1000 J | 737.561 ft·lb |
| 10000 J | 7,375.61 ft·lb |
| 100000 J | 73,756.103 ft·lb |
规则