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 = |
|---|---|---|
| Z | 1:220 | 18.3 scale feet |
| N | 1:160 | 13.3 scale feet |
| HO | 1:87 | 7.25 scale feet |
| S | 1:64 | 5.33 scale feet |
| OO (British) | 1:76 | 6.33 scale feet |
| O | 1:48 | 4.0 scale feet |
| G (Garden) | 1:22.5 | 1.875 scale feet |
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" → 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, a real freight train running 1 mile would cover about 5.3 inches on your HO layout — so a 137-inch layout is quite generous for a point-to-point operation.
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 (articulated steamers, full-length passenger cars) need larger minimum radii — check manufacturer specifications.
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: Bendable to any radius, lower cost per foot, requires careful planning and spiking to roadbed — preferred for permanent layouts