Calculate wheelchair ramp slope ratio (1:12 ADA), total ramp run length, landing platform rest stops, handrail requirements, and construction dimensions.
288 inches total run
289.0 inches travel surface
Building a ramp too steep (such as 1:6 or 1:8) forces manual wheelchair occupants to push with extreme physical exertion, risking backward tip-overs or brake slippage when descending in rain. Our calculator enforces the ADA standard 1:12 running slope ratio, guaranteeing a safe, gentle 4.76-degree incline grade.
ADA guidelines dictate that no single continuous ramp run may exceed 30 inches of vertical rise or 30 feet of horizontal run without a level resting platform. Our engine automatically checks total rise and inserts the required 60" × 60" intermediate landings or switchbacks into your spatial plan.
Contractors frequently order decking boards matching only the horizontal yard footprint, coming up short on angled surface decking. By solving the true hypotenuse diagonal travel distance via the Pythagorean theorem, this calculator ensures you purchase the exact lumber lengths for framing stringers and surface planks.
Whenever a ramp exceeds 6 inches of vertical rise, building codes mandate continuous handrails on both sides, mounted between 34 and 38 inches high, with a minimum 12-inch horizontal extension past the ramp bottom. Our tool itemizes handrail linear footage and safety curb requirements.
| Vertical Rise | Slope Ratio | Horizontal Run | Incline Angle | Rest Landings | Handrails | Application |
|---|---|---|---|---|---|---|
| 6 inches (1 step) | 1:12 | 6.0 feet (72") | 4.76° (8.33%) | 0 required | Optional (Rise ≤ 6") | Sidewalk Curb |
| 12 inches (2 steps) | 1:12 | 12.0 feet (144") | 4.76° (8.33%) | 0 required | Mandatory (Both Sides) | Low Porch Entry |
| 24 inches (3-4 steps) | 1:12 | 24.0 feet (288") | 4.76° (8.33%) | 0 required | Mandatory (Both Sides) | Standard Home Deck |
| 36 inches (5-6 steps) | 1:12 | 36.0 feet (432") | 4.76° (8.33%) | 1 Landing (5' × 5') | Mandatory (Both Sides) | Elevated Foundation |
| 48 inches (6-8 steps) | 1:12 | 48.0 feet (576") | 4.76° (8.33%) | 1-2 Switchbacks | Mandatory (Both Sides) | Commercial Building |
Measure the plumb vertical distance in inches from the ground or sidewalk to the finished door threshold.
Choose standard ADA 1:12 (1 foot of run per 1 inch of rise) or residential easy-push 1:16 slope.
Multiply total rise by the slope factor to determine the horizontal footprint in feet and inches.
Verify if vertical rise exceeds 30" or run exceeds 30'; add 60" × 60" flat resting landings if required.
Inspect diagonal travel length, continuous handrail requirements, total deck square footage, and lumber order.
Instantly validates slope ratios, maximum 30-inch rise limits, and 36-inch minimum clear widths.
Calculates required intermediate resting stops (60" × 60") for straight, L-shape, and 180° U-turn layouts.
Computes true sloped walking surface hypotenuse $\sqrt{\text{Rise}^2 + \text{Run}^2}$ for exact lumber ordering.
Real-time SVG schematic dynamically illustrates vertical rise, horizontal run, slope angle, and handrails.
