Model railway scale calculator
Convert between the real world and the layout.
Prototype would be doing
106.6 km/h
| mph for the prototype | 66.21 |
| Model speed | 200 mm/s |
| Crosses 1 m of layout in | 5 s |
At 1:148 (N), standard gauge (1435 mm) scales to 9.7 mm, against the 9 mm track the scale is sold on — stock at this ratio is therefore about 8% oversize for its own track. British prototypes were too small to house the motors available at 1:160, so Britain went oversize and kept the 1:160 track.