How Long a Wheelchair Ramp for 4 steps?

Four steps with 7 inch risers are a 28 inch rise, which needs a 28 ft wheelchair ramp at the 1:12 maximum slope, or 33 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)

28.0 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% extra198 lineal ft of boards, rounded up
Joists per run (16 in centers)4 joists
Joist lumber (size from a span table), with 10% extra124 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): 28.1 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: 33.0 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: 38.0 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: 60 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: 61 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

28 ft ramp

Four steps: close to the limit for one run

Four 7 inch risers add up to 28 inches, which fits in one 28 ft run with 2 inches to spare under the 30 inch limit. With 7.75 inch risers the same four steps climb 31 inches, which needs 2 runs and a footprint of 41 ft instead of 33 ft.

So for four steps the riser height decides whether you need a landing part way. Measure the whole height from the ground to the porch floor and use that, not the step count.

Ramp length for 4 steps by riser height

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

Riser height	Total rise	1:12 ramp	1:16 ramp	1:20 ramp	Runs	Footprint at 1:12
6 in	24 in	24 ft	32 ft	40 ft	1	29 ft
6.5 in	26 in	26 ft	34.67 ft	43.33 ft	1	31 ft
7 in	28 in	28 ft	37.33 ft	46.67 ft	1	33 ft
7.25 in	29 in	29 ft	38.67 ft	48.33 ft	1	34 ft
7.5 in	30 in	30 ft	40 ft	50 ft	1	35 ft
7.75 in	31 in	31 ft	41.33 ft	51.67 ft	2	41 ft

28 inch rise at each slope

Slope	Ramp length (run)	Along the surface	Percent	Angle	Runs	Footprint with landings
1:12 (ADA maximum)	28 ft	28.10 ft	8.3%	4.8°	1	33 ft
1:16	37.33 ft	37.41 ft	6.3%	3.6°	1	42.33 ft
1:20	46.67 ft	46.72 ft	5.0%	2.9°	1	51.67 ft

Is a shorter ramp too steep?

Ramp length	Slope	Percent	Angle	Within 1:12?
24 ft	1:10.3	9.7%	5.6°	No, 4 ft too short
26 ft	1:11.1	9.0%	5.1°	No, 2 ft too short
28 ft	1:12	8.3%	4.8°	Yes
32 ft	1:13.7	7.3%	4.2°	Yes

Other step counts (7 inch risers)

Steps	Rise	1:12 ramp	Runs	Footprint
1 step	7 in	7 ft	1	12 ft
2 steps	14 in	14 ft	1	19 ft
3 steps	21 in	21 ft	1	26 ft
5 steps	35 in	35 ft	2	45 ft

Know the height in inches? See a ramp for 28 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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Portable folding ramp

Frequently asked questions

How long of a ramp do I need for 4 steps?

Measure the total height. 4 steps with 7 inch risers are 28 inches, which needs a 28 ft ramp at 1:12 (1 foot of ramp per inch of rise). With 7.75 inch risers the rise is 31 inches and the ramp is 31 ft.

Is a ramp for 4 steps one run or two?

One run if the total rise is 30 inches or less, two if it is more. Four 7 inch risers are 28 inches (one run of 28 ft); four 7.75 inch risers are 31 inches (two runs).

How high are 4 steps?

Usually 24 to 31 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.

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