Hobbies · Model railroading
Model railroad scale miles converter.
Choose a scale and a distance, and the converter turns real distance into model length or model length into real distance. Example: a scale mile in HO is 60.62 feet of model track (727.4 inches). A 12-foot run of HO track represents 0.198 scale miles, or about 1,045 feet.
Your numbers
Result
Working out the result.
How the conversion is calculated
A model railroad scale is a ratio: one unit on the model stands for that many units on the real railroad. The NMRA lists the ratios in S-3.2, Track, Standard Scale (28 June 2026): O 1:48, S 1:64, OO 1:76.2, HO 1:87.1, TT 1:120, N 1:160 and Z 1:220. Real distance divided by the ratio is model distance, and the reverse.
A statute mile is 5,280 feet, so a scale mile in a given scale is 5,280 feet divided by the ratio. In HO that is 5,280 / 87.1 = 60.62 feet, or 727.4 inches. The page converts kilometres and metres using the international foot of exactly 0.3048 metre, and inches to millimetres at exactly 25.4. It prints scale miles to four decimals, and a table of one scale mile in each scale.
The ratio the page uses for HO is the NMRA's 1:87.1. European makers use the NEM ratio of exactly 1:87, which gives answers about 0.1% different. For layout planning that is far below the error of any tape measure.
Worked examples with real numbers
- One scale mile in HO. 5,280 / 87.1 = 60.62 feet of model track, which is 727.4 inches.
- A 12-foot run of HO track. 12 × 87.1 = 1,045.2 feet of real railroad, or 0.198 scale miles.
- 100 kilometres in HO. 100 km is 328,084 feet; divided by 87.1 that is 3,766.8 feet of model, nearly 3,767 feet. No home layout runs that far, so the distance is for the story, not the track plan.
- One scale mile in N. 5,280 / 160 = 33 feet. A 10-foot N-scale mainline is 0.30 scale miles.
Scale miles by scale
| Scale | Ratio | One scale mile |
|---|---|---|
| O | 1:48 | 110 ft |
| S | 1:64 | 82.5 ft |
| OO | 1:76.2 | 69.29 ft |
| HO | 1:87.1 | 60.62 ft |
| TT | 1:120 | 44 ft |
| N | 1:160 | 33 ft |
| Z | 1:220 | 24 ft |
What this calculator leaves out
It converts distances only. It does not adjust for compressed models, selective compression of a layout, or the operating time a scale mile takes at a given scale speed. A forum rule of "60 feet to the mile in HO" is the rounded form of the same arithmetic.
Frequently asked questions
How long is a scale mile in HO?
5,280 feet divided by 87.1 is 60.62 feet, or 727.4 inches, of model track. Many modellers round to 60 feet.
How long is a scale mile in N?
5,280 divided by 160 is exactly 33 feet of model track.
Which scale ratio does the tool use for HO?
The NMRA ratio of 1:87.1 from S-3.2. The European NEM standard uses 1:87, which differs by about 0.1%.
How do I convert model feet to real feet?
Multiply by the ratio. 12 feet of HO track is 12 times 87.1, or 1,045.2 feet of real railroad.
Does the converter handle metric?
Yes. Enter metres or kilometres for a real distance, or millimetres or centimetres for a model length. It uses an exact foot of 0.3048 metre.
Why do forum posts say 60 feet to the mile?
That is 5,280 / 87.1 = 60.62 rounded down. It is a good rule of thumb for HO and slightly short of the exact figure.
Sources
Retrieved
- NMRA S-3.2: Track, Standard Scale (28 June 2026) — the scale ratios O 1:48 to Z 1:220 (read 2026-10-26)
Ratios from NMRA S-3.2
Not affiliated with the NMRA. The ratios were read on 26 October 2026. Nothing you type is sent or stored.