How Long a Wheelchair Ramp for 1 step?

One step 7 inches high is a 7 inch rise, which needs a 7 ft wheelchair ramp at the 1:12 maximum slope, or 12 ft with the 5 ft top landing. Step heights differ from house to house (the chart below runs from 6 to 7.75 inches), so measure the total height from the ground to the door: the ramp needs 1 foot for every inch.

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Example job shown. Change the numbers to match yours.

Ramp length (horizontal run)
7.0 ft
1 inch of rise needs 12 inches of ramp. Measure this along the ground, not along the sloping surface
What to buy
  • Decking, with 10% extra50 lineal ft of boards, rounded up
  • Joists per run (16 in centers)4 joists
  • Joist lumber (size from a span table), with 10% extra31 lineal ft of lumber, rounded up
  • 80 lb bags of concrete mix for those landings (0.6 ft³ each)16 bags
Walking surface length (along the slope)
7.0 ft
Separate ramp runsEach run climbs no more than 30 in
1 run
Intermediate landings (5 × 5 ft)
0 landings
Landings in total (5 ft × 5 ft clear space at each)1 top + 0 intermediate + 1 clear space at the bottom. The concrete and bag counts below cover the top and intermediate landing (1), not the bottom one
2 landings
Total footprint with a 5 ft top landing
12.0 ft
Footprint with the 5 ft clear space at the bottom as wellThe bottom 5 ft is level ground or a landing you pour or lay separately: it is not in the concrete below
17.0 ft

Materials (wood ramp runs, concrete landings)

Deck boards (5/4×6, laid across the ramp)Each row is one board 3.0 ft long
15 board rows
Concrete for the top landing (1 at 5 ft × 5.0 ft, 4 in thick, +10%)
9.2 ft³
Same concrete in cubic yards
0.34 yd³

Requirements to check

Handrails needed (rise over 6 in)
Yes, both sides
Handrail length, both sides, with 12 in extensionsEach side: the walking surface length plus 12 in at the top and bottom of every run (ADA Standards 405.8 and 505.10.1). Rail stock, posts and brackets are extra
19 lineal ft
Clear width
36 in
  • Size the joists for their span from a span table or your plans examiner.
  • 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. The materials list is a planning estimate for a wood-framed ramp with a concrete top landing and any intermediate landings: the concrete covers the top and intermediate landings only, not the level 5 ft at the bottom. It leaves out posts, footings and guards (the handrail length is given above), whose spacing and size depend on your loads, frost depth and local code.

Before you buy: round up to whole packs, check the size printed on the label, and add a little spare. Your supplier has the final say.

Blueprint

7 ft0.6 ft5 ft clear

7 ft ramp

One step: measure it before you buy

A single step is the case where an inch matters most. At 6 inches high the ramp is 6 ft; at 7.75 inches, the tallest riser the IRC allows in a house, it is 7.75 ft. A 7 inch step sits between them at 7 ft.

Handrails are required when the rise is more than 6 inches. So a 6 inch step is just inside the line and a 7 inch step is over it: the example on this page needs handrails on both sides.

Ramp length for 1 step by riser height

Steps are not all the same height, so find your riser in the first column or measure the total rise.

Riser heightTotal rise1:12 ramp1:16 ramp1:20 rampRunsFootprint at 1:12
6 in6 in6 ft8 ft10 ft111 ft
6.5 in6.5 in6.5 ft8.67 ft10.83 ft111.5 ft
7 in7 in7 ft9.33 ft11.67 ft112 ft
7.25 in7.25 in7.25 ft9.67 ft12.08 ft112.25 ft
7.5 in7.5 in7.5 ft10 ft12.5 ft112.5 ft
7.75 in7.75 in7.75 ft10.33 ft12.92 ft112.75 ft

7 inch rise at each slope

SlopeRamp length (run)Along the surfacePercentAngleRunsFootprint with landings
1:12 (ADA maximum)7 ft7.02 ft8.3%4.8°112 ft
1:169.33 ft9.35 ft6.3%3.6°114.33 ft
1:2011.67 ft11.68 ft5.0%2.9°116.67 ft

Is a shorter ramp too steep?

Ramp lengthSlopePercentAngleWithin 1:12?
3 ft1:5.119.4%11.0°No, 4 ft too short
5 ft1:8.611.7%6.7°No, 2 ft too short
7 ft1:128.3%4.8°Yes
11 ft1:18.95.3%3.0°Yes

Other step counts (7 inch risers)

StepsRise1:12 rampRunsFootprint
2 steps14 in14 ft119 ft
3 steps21 in21 ft126 ft
4 steps28 in28 ft133 ft
5 steps35 in35 ft245 ft

Know the height in inches? See a ramp for 6 inches of rise, or the ramp length and slope guide. The stair calculator works out riser heights from a total rise.

Want to change anything else? The calculator above is the full Wheelchair Ramp Calculator: edit any number and the results update instantly.

Tools & materials for this project

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Frequently asked questions

How long of a ramp do I need for 1 step?

Measure the total height. One step 7 inches high is 7 inches, which needs a 7 ft ramp at 1:12 (1 foot of ramp per inch of rise). A 7.75 inch step needs 7.75 ft.

Does a ramp over one step need handrails?

It depends on the height. Under the ADA figures handrails are needed when the rise is more than 6 inches, so a 6 inch step does not need them and a 7 inch step does.

How high is 1 step?

Usually 6 to 7.75 inches, at 6 to 7.75 inches a riser. Count every riser, including the last one up onto the porch or threshold, or simply measure from the ground to the door sill.

Related sizes and guides

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.