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Calcimator

Model Railroad Track Calculator

Plan model railroad layouts with minimum curve radius, track spacing, grade limits, and turnout sizing by scale.

Inputs

Results

Recommended Min Radius

18"

Track Center Spacing

2"

Max Train Length60"
Turnout Length10.8"
Max Grade4%
How to Use This Calculator
  1. Enter Scale, N Scale (1:160), and HO Scale (1:87).
  2. Set O Scale (1:48), G Scale (1:22.5), and Table Width (inches).
  3. Adjust Table Length (inches), Min Curve Radius (inches) as needed.
  4. Review Recommended Min Radius () and Track Center Spacing ().
  5. Use Max Train Length () and Turnout Length () to inform your decision.

How the result changes with Min Curve Radius (inches)

Min Curve Radius (inches)Recommended Min RadiusTrack Center Spacing
1518"2"
3939"2"
6767"2"
9191"2"

What each input means

Scale
Model railroad scale (affects all measurements)
Table Width (inches)
Width of your layout table or benchwork
Table Length (inches)
Length of your layout table or benchwork
Min Curve Radius (inches)
Minimum curve radius you want to use (larger = more realistic)

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Scale = 2, Table Width (inches) = 48, Table Length (inches) = 96, Min Curve Radius (inches) = 18 = 4 input(s) provided
  2. Calculate Recommended Min Radius
    Recommended Min Radius
    18 = 18
  3. Calculate Track Center Spacing
    Track Center Spacing
    2 = 2
  4. Calculate Max Train Length
    Max Train Length
    60 = 60
  5. Calculate Turnout Length
    Turnout Length
    10.8 = 10.8

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