Model Train Calculators
Free online model train calculators.
Convert between scales, calculate track lengths, grade percentages, and layout dimensions for model railroaders.
Model Train Scale Speed Calculator
Convert prototype locomotive speed to true model speed for HO, N, O, G, S, and Z scales. Shows results in mph, inches per second, and cm per second.
DCC Decoder Amperage Calculator
Pick a DCC decoder by motor stall amps and continuous draw. Get headroom advice for HO, N, O scale locos and avoid burned-out decoders from undersizing.
Model Train Minimum Curve Radius Calculator
Calculate minimum curve radius for model trains by car length and scale. Find the tightest safe radius for HO, N, O, and other scales without derailment.
Model Train Ballast Volume Calculator
Calculate ballast volume needed for model railroad track by scale, track length, and profile depth. Returns required amount in quarts, liters, and bags.
Model Train Grade/Climb Calculator
Calculate model railroad grade from run and rise in inches. Returns recommended max grade by scale (HO, N, O, G) and car count a locomotive can pull uphill.
Model Train Layout Scenery Area Calculator
Calculate net scenery area for a model train layout by subtracting track and structures from total area. Returns square inches of groundcover and foam needed.
Model Train Power Supply Calculator
Calculate the right power supply wattage and amperage for your model train layout based on scale, locomotives, and accessories.
Model Train Scale Converter
Convert real-world dimensions to model train scale and back. Covers HO (1:87), N (1:160), O (1:48), Z (1:220), G (1:22.5), and any custom scale ratio.
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.