Ruling Grade

Ruling Grade is an offline-first grade-ruler for basement model-railroad builders who engineer one named mainline run at a time. Cold start opens a fullscreen track profile with oversized rise and run fields, a live percent-grade needle, scale-aware max-grade bands, and the active segment name locked at the top. Set climb over distance, check curve radius, turnout number, helix rise, and deck clearance without leaving the ruler surface. Create named layout projects with scale presets for HO, N, O, S, and G. Each layout stores default minimum radius, maximum grade, and rolling-stock height. Build an ordered mainline segment strip showing length, rise, grade, and cumulative climb—tap any row to load it on the ruler. Use the curve-radius bench to compare centerline radius against scale minimums, add an easement note, and get a clear pass/fail chip. Open the turnout size card for frog number, effective divergent radius, and fit check against the segment and yard throat. Plan helixes with loop count, track-to-track deck separation, loop circumference from radius, resulting grade, and leftover clearance after roadbed and cork. Verify deck clearance with upper-deck soffit height, railhead-to-railhead gap, tallest car or loco height, and go/no-go space remaining. The ruling-grade report auto-picks your steepest mainline segment and lists the second-worst grade, tightest radius, and helix bottleneck on one summary card. Seed layouts—HO basement dogbone, N shelf helix, and O garage point-to-point—make the ruler useful on first launch. Every layout, segment, and helix stays on your device. Copy a plain-text grade card for shop notes. No account, no cloud, typed input only—know your layout’s true ruling grade, tightest curve, and helix deck gap before you cut roadbed.