ScaledRailScale describes model size.
Scale compares the size of a model with the size of the real train. Gauge measures the distance between the rails.
| Scale | Ratio in the NMRA guide |
|---|---|
| O | 1:48 |
| HO | 1:87.1 |
| N | 1:160 |
| G | 1:22.5, with other large scale ratios also used |
The NMRA guide lists Z among the main scales. This source gives no Z ratio, so this table omits it.
Read each item label.
A scale label does not confirm track gauge or compatibility. Check the maker details before you join items in a layout.
Source: nmra-start. Read 2026-11-15.
Questions from the workbench.
Are scale and gauge the same?
No. Scale compares model size with the real train. Gauge measures the distance between the rails.
What HO ratio does the NMRA guide list?
The NMRA guide lists HO at 1:87.1.