Tools

Convert real-world and model dimensions across HO, N, O, S, G, Z and more.

Convert a measured model speed into real-world scale mph.

Check car overhang on a given curve radius, or solve backward for the minimum radius your clearance allows.

Find a hand-bent curve's exact radius from a measured chord and middle ordinate.

Convert a prototype curve's degree of curvature to a radius, in real or model scale.

Find the length and offset for a smooth transition into a curve, per NEM 113.

Minimum center-to-center spacing for parallel curved tracks.

Percent grade and rise-over-run for a given length and height change.

Grade, loop count, and total length for a helix of a given radius and rise.

Full NMRA TN-12 turnout geometry: frog, switch, closure rail, gauge points and crossover spacing.

Prototype outer-rail banking for a curve's speed and radius, scaled to your model.

Total current draw vs. booster capacity, with a safety margin you set.

Voltage drop, max run length, or minimum wire gauge for your DCC bus or feeders.

Series resistor for your LED, snapped to the nearest standard E12 value.

Capacitance, hold time, or voltage droop for a decoder keep-alive circuit.

Build or decode a CV29 value from direction, speed table, RailCom, and addressing options.

Convert a target acceleration or braking time into the right CV3/CV4 value.

Convert a 4-digit locomotive address to CV17/CV18, or decode it back.

Generate all 28 CV67-94 speed-step values plus CV66/CV95 trim from two endpoints.

Ballast volume and bag/bottle count from your track length, scale, and a sourced ballast profile.

How many bags of ground foam or static grass a project needs, adjusted for how thickly you apply it.

Two-part resin volume for a pond or river, split into pour layers and mix ratio.

Recommended rolling-stock weight per NMRA RP-20.1 (US) or MOROP NEM 302 (European), plus estimated figures for 9 UK scales.