♿ Wheelchair Ramp Calculator
Enter the vertical rise and a slope to get the ramp's length, horizontal run and incline angle, with an ADA compliance check.
Ramp length
361.2 in
30 ft 1 in
Horizontal run
360 in
30 ft 0 in
Incline angle
4.8°
✓ Meets the ADA 1:12 maximum slope for public wheelchair ramps.
A ramp\'s run is the rise times the slope ratio (1:12 means 12 units of run per 1 of rise), and the sloped ramp length is √(rise² + run²). The ADA limit for public ramps is 1:12 (≈4.8°), with a maximum 30-inch rise before a level landing. Check your local building code — requirements vary. 🔒 In your browser.
How the wheelchair ramp calculator works
A ramp trades height for length: the gentler the slope, the longer it must be. For a slope written as 1:N, the horizontal run is the rise times N, and the actual sloped ramp length is √(rise² + run²). The tool also gives the incline angle and checks it against the ADA maximum of 1:12 (about 4.8°) for public, unassisted wheelchair use. Pick a common slope or a gentler one and read off the run and ramp length you need.
The ADA limits a single ramp run to a 30-inch rise before a level landing, requires handrails above a 6-inch rise, and caps the slope at 1:12 for public unassisted use (steeper ratios like 1:8 are only for short, occupied or unoccupied situations). Building codes vary by country and setting — treat this as a planning aid and confirm your local requirements.
Frequently asked questions
How long should a wheelchair ramp be?
At the ADA 1:12 slope, the ramp needs 12 inches of run for every 1 inch of rise — so a 30-inch rise needs a 30-foot run. The sloped ramp itself is slightly longer: √(rise² + run²). Enter your rise for the exact figures.
What is the ADA ramp slope?
The maximum is 1:12 — one unit of rise per twelve of run, about a 4.8° incline — for public, unassisted wheelchair ramps. Gentler slopes (1:16 to 1:20) are easier still; steeper ones are only allowed in limited, assisted or temporary cases.
How do I calculate ramp length from rise and slope?
Run = rise × slope ratio (12 for 1:12). The sloped ramp length is √(rise² + run²), which is just a little more than the run. This calculator returns run, ramp length and the incline angle.
What is the maximum rise for a single ramp run?
The ADA allows a 30-inch (760 mm) maximum rise for one ramp run before a level landing is required, with a 30-foot maximum horizontal run at 1:12. Longer climbs use a series of ramps and landings.
Do I need handrails on a ramp?
Under the ADA, ramps with a rise greater than 6 inches need handrails on both sides. Requirements vary by jurisdiction and by whether the ramp is residential or public, so check your local building code.