Model Train Track Length Calculator
Calculate total track length for your model train layout in scale feet and real inches.
Plan your loop, siding, and yard track requirements.
Planning track for your model railroad layout:
Model train track length planning involves two measurements you need to think about simultaneously: the actual physical length of track on your layout table, and what that represents in the modeled world (scale feet). Getting both right helps you plan realistic routes and order the right amount of track.
Common model railroad scales and their ratios:
| Scale | Ratio | 1 real inch = | Real track for 1 scale mile |
|---|---|---|---|
| Z | 1:220 | 18.3 scale feet | 288" (24 ft) |
| N | 1:160 | 13.3 scale feet | 396" (33 ft) |
| TT | 1:120 | 10.0 scale feet | 528" (44 ft) |
| HO | 1:87 | 7.25 scale feet | 728" (61 ft) |
| OO (British) | 1:76 | 6.33 scale feet | 834" (69 ft) |
| S | 1:64 | 5.33 scale feet | 990" (82 ft) |
| O | 1:48 | 4.0 scale feet | 1,320" (110 ft) |
| Gauge 1 | 1:32 | 2.67 scale feet | 1,980" (165 ft) |
| G (Garden) | 1:22.5 | 1.875 scale feet | 2,816" (235 ft) |
Scale length formula:
Scale length (feet) = Real length (inches) × Scale ratio ÷ 12
For HO scale (1:87):
Scale feet = Real inches × 87 ÷ 12 = Real inches × 7.25
Worked example, a simple oval layout:
An HO layout with:
- 2 straight sections: 12" each = 24"
- 4 curved sections (18" radius): each section is π × 18 × 2 ÷ 4 ≈ 28.3", so 4 × 28.3 = 113"
- Total real length: 24 + 113 = 137 inches
- Scale length: 137 × 7.25 = 993 scale feet (~0.19 scale miles)
For context, one scale mile in HO takes 728 inches of real track, which is just over 60 feet. That 137-inch oval represents less than a fifth of a mile, and you would need five and a half of them laid end to end to model a single mile. This is the thing that catches people out when they first plan a layout: even a wall-length run is a very short piece of railroad, which is why serious layouts lean on staging yards and scenic dividers to imply distance rather than trying to model it.
Minimum curve radius by scale:
| Scale | Minimum (tight) | Comfortable | Recommended |
|---|---|---|---|
| N | 9.75" | 11" | 15"+ |
| HO | 15" | 18" | 22"+ |
| O | 27" | 31" | 42"+ |
Longer locomotives such as articulated steamers and full-length passenger cars need larger minimum radii, so check the manufacturer’s specification before committing to a curve.
Track sectional vs. flex track:
- Sectional track (Atlas, Kato, Bachmann EZ-Track): Fixed lengths and curves, easy to plan with, slightly higher cost per foot, good for beginners
- Flex track: bends to any radius and costs less per foot, but needs careful planning and pinning to the roadbed. The usual choice for a permanent layout
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