Railway Modelling Calculators
Essential calculators for model railway layouts — track, curves, gradients, platforms, bridges, signals and baseboards.
Track Length Calculator
Calculate total track length needed for your layout plan including sidings.
Curve Radius Calculator
Find the minimum curve radius for your rolling stock and scale.
Gradient Calculator
Calculate gradient percentages and rise-over-run for inclines and hills.
Point Spacing Calculator
Work out correct spacing between turnouts and crossings for smooth operation.
Platform Length Calculator
Calculate scale platform length based on train lengths and number of coaches.
Bridge Calculator
Size bridges for your layout — span, clearance height and approach grades.
Tunnel Calculator
Calculate tunnel bore dimensions, portal size and minimum length at scale.
Catenary Calculator
Calculate overhead wire heights, mast spacing and wire sag for electrified lines.
Signal Spacing Calculator
Work out realistic signal placement distances for your scale and era.
Baseboard Calculator
Plan baseboard dimensions, support spacing and materials for your layout.
10 free calculators in Railway Modelling
Model Railway Layout Planning
Planning a model railway layout involves a surprising amount of mathematics. Track geometry, gradient calculations, clearance dimensions and realistic spacing all need to be worked out before you start laying track. These calculators cover the most common planning tasks for OO, HO, N and O gauge layouts.
In OO gauge (1:76, 16.5mm track), the minimum recommended curve radius for reliable running is around 438mm (2nd radius), though larger radii of 600mm+ look far more realistic. For N gauge (1:148, 9mm track), minimum radius drops to around 228mm. Our curve radius calculator helps you find the sweet spot between space constraints and realistic operation.
Gradients are critical for reliable running. Most model locomotives can handle 1 in 30 (3.3%) as an absolute maximum, but 1 in 50 (2%) or gentler is recommended for consistent operation with long trains. The gradient calculator shows you exactly how much height you gain over a given run length, which is essential when planning multi-level layouts.