长度是一个基本的物理量，可测量两个点之间的距离。它是国际单元（SI）中的七个基本单元之一，仪表（m）是其基本单元。
1 ft = 304,800 µm
1 µm = 3.2808e-6 ft
例子:
将15 脚转换为千分尺：
15 ft = 4,572,000 µm
| 脚 | 千分尺 |
|---|---|
| 0.01 ft | 3,048 µm |
| 0.1 ft | 30,480 µm |
| 1 ft | 304,800 µm |
| 2 ft | 609,600 µm |
| 3 ft | 914,400 µm |
| 5 ft | 1,524,000 µm |
| 10 ft | 3,048,000 µm |
| 20 ft | 6,096,000 µm |
| 30 ft | 9,144,000 µm |
| 40 ft | 12,192,000 µm |
| 50 ft | 15,240,000 µm |
| 60 ft | 18,288,000 µm |
| 70 ft | 21,336,000 µm |
| 80 ft | 24,384,000 µm |
| 90 ft | 27,432,000 µm |
| 100 ft | 30,480,000 µm |
| 250 ft | 76,200,000 µm |
| 500 ft | 152,400,000 µm |
| 750 ft | 228,600,000 µm |
| 1000 ft | 304,800,000 µm |
| 10000 ft | 3,048,000,000 µm |
| 100000 ft | 30,480,000,000 µm |
规则