Track Length Calculator — Layout Planning
Calculate total track length needed for your model railway layout plan including sidings.
How We Calculate This
Calculates main line track length from your baseboard dimensions and track plan style, then adds siding lengths. The oval is treated as a stadium shape (a discorectangle): two semicircular ends joined by two straights, the largest curve that fits the board width.
Formula
- Curve radius r = ½ × Width (floored at the gauge minimum: OO 438mm, N 228mm, O 876mm)
- Each straight = Length − 2r (the curved ends use up the curve diameter)
- Oval main line = 2 × Straight + 2 × π × r (the two semicircles make one full circle)
- Sidings total = Number of sidings × Average siding length
- Total track = Main line + Sidings total
- Flex track pieces = Total ÷ 914mm (Peco Streamline, OO and N)
Figure-of-eight, dogbone, point-to-point and complex multi-track are rough planning estimates — always confirm against a scale track plan and add 15-20% for cutting and adjustments.
Frequently Asked Questions
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Last updated: February 2026
All calculations are estimates. Always verify quantities before purchasing materials.