WeekendCalc

Wheelchair Ramp Calculator

Enter the total height you need to climb. You get how long the ramp has to be at your chosen slope, how many separate runs and landings it needs, and the total space it will occupy.

Your project

Results

Ramp length (horizontal run)
24.0 ft
1 inch of rise needs 12 inches of ramp
Walking surface length (along the slope)
24.1 ft
Separate ramp runsEach run climbs no more than 30 in
1 run
Intermediate landings (5 × 5 ft)
0 landings
Total footprint with a 5 ft top landing
29.0 ft

Requirements to check

Handrails needed (rise over 6 in)
Yes, both sides
Clear width
36 in
  • Under the ADA, the maximum slope is 1:12, the maximum rise of one run is 30 inches, landings must be at least 60 inches long and as wide as the ramp, and the clear width must be at least 36 inches. Residential rules differ by place, so check local codes, and allow 5 ft of clear space at the bottom.

How this calculator works

Accessibility guidelines set the maximum slope of a ramp at 1:12: for every inch of rise, 12 inches of ramp. A gentler slope (1:16 or 1:20) is much easier to climb in a manual wheelchair and safer on the way down. A single run may rise at most 30 inches, and then a level landing (at least 60 × 60 inches) is needed before the next run.

ramp length (ft) = rise (in) × slope ÷ 12 runs = ⌈rise ÷ 30⌉

Worked example: a 24 in rise at 1:12 needs a 24 ft ramp in one run, plus a 5 ft landing at the top: 29 ft in all. A 36 in rise at 1:12 needs 36 ft of ramp in two runs, with a 5 ft landing in between and another at the top: 46 ft.

Tips before you buy

  • A longer, gentler ramp is nearly always easier to use. If space is tight, consider a switchback (a U-turn at a landing) or a platform lift.
  • Edge protection (a 2 in curb or rail) keeps wheels from rolling off the side, and a non-slip surface matters in wet and icy weather.
  • Permanent ramps usually need a permit. Treated lumber, aluminium and concrete are the usual materials: aluminium modular systems can be moved later.
  • Measure the rise carefully from the ground at the bottom to the finished floor inside the doorway, including the threshold.

Tools & materials for this project

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Modular aluminum rampThreshold rampNon-slip ramp tapeHandrailsPortable folding ramp

Frequently asked questions

How long does a wheelchair ramp need to be?

For a 1:12 slope, 1 foot of ramp for every inch of rise. A 24 inch rise needs a 24 ft ramp, and 6 inches needs 6 ft.

What is the maximum slope for a wheelchair ramp?

1:12 (about 8.3%) under the ADA and most codes. A gentler slope is better where there is room.

Do I need a landing?

Yes: at the top and bottom, at any change of direction, and at least every 30 inches of rise. Landings must be at least 60 inches long and as wide as the ramp.

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Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.