自建或托管机房中常用的机柜规格为19英寸机柜（宽度≈48.26cm），42U高度。1Unit=4.445cm=1.75英寸。选购需注意服务器机柜的进深通常为800mm。
| 19英寸机柜尺度参考 | |||
| 称号 | 类型 | 规范尺度/mm（高/宽/深） | 备注 |
| 标准机柜 | 18U | 1000x600X600 | |
| 24U | 1200x600X600 | ||
| 27U | 1400x600X600 | ||
| 32U | 1600x600X600 | ||
| 37U | 1800x600X600 | ||
| 42U | 2000x600X600 | ||
| 服务器机柜 | 42U | 2000x800X800 | |
| 37U | 1800x800X800 | ||
| 24U | 1200x600X800 | ||
| 27U | 1400x600X800 | ||
| 32U | 1600x600X800 | ||
| 37U | 1800x600X800 | ||
| 42U | 2000x600X800 | ||
| 壁挂机柜 | 6U | 350x600X450 | |
| 9U | 500x600X450 | ||
| 12U | 650x600X450 | ||
| 15U | 800x600X450 | ||
| 18U | 1000x600X450 | ||
