Convert Actual Curve Radius to Scale Radius


Enter the actual radius you want to convert and the units of measure:





Enter the units of measure you want the converted radius to be displayed in:



If the scale ratio you want to convert to is not listed in the table at the bottom of the page, you can enter it manually.

For example, if you want to calculate a ratio of 1:100, simply enter 100 in the box below:








Note: The scale calculations made on these pages use the scale ratios in the table below. As these ratios are used, a length calculated in 4mm scale will not be twice the same length calculated in 2mm scale.

2mm scale (US/EU N)1:160
2mm scale (2mm FS)1:152.3
2mm scale (British N)1:148
3mm scale (British TT)1:101.6
3.5mm scale (HO)1:87.1
4mm scale (OO, EM, P4)1:76.2
7mm scale (O)1:43.5




Application created by John Donnelly, Copyright © 2020, Version 1.0.201116.0