ADA Ramp Run & Landing Calculator
Calculate the exact ramp length needed for a given vertical rise at a chosen slope, the number of level landings required, and check the result against the ADA Standards for Accessible Design (2010).
Enter the total vertical rise to calculate the ramp length needed at a given slope, the number of level landings required, and check the result against the ADA Standards for Accessible Design (2010).
How This Calculator Works
ADA guidelines cap the rise of a single ramp run at 30 inches (760 mm), regardless of slope. The calculator divides your total rise by this maximum, rounds up to a whole number of runs, and then splits the total rise evenly across them — this keeps every run's rise identical and under the cap, the same logic used for equal stair risers.
A slope of 1:12 means 12 inches (or 12 mm) of horizontal run for every 1 inch (or 1 mm) of vertical rise. Multiplying each run's rise by the slope ratio gives its horizontal length; the ramp's actual surface length is slightly longer than this horizontal projection, since it's the hypotenuse of the rise and the run.
A level landing is required at the top and bottom of every ramp run, and wherever the ramp changes direction — so a ramp built from N runs needs N + 1 landings. Each landing must be at least 60 inches (1525 mm) long in the direction of travel and at least as wide as the ramp itself, giving wheelchair users a place to rest and turn.
1:12 is the maximum slope allowed for a new, code-compliant accessible ramp — a gentler ratio like 1:16 or 1:20 is also compliant and easier to climb, just longer for the same rise. Ramp width is measured as the clear width between handrails, with 36 inches (915 mm) the standard minimum, and handrails are required on both sides whenever the total rise exceeds 6 inches (150 mm).
Frequently Asked Questions
About this calculator
This calculator turns a single measurement — the total vertical rise — into a complete ADA-compliant ramp layout: the minimum number of ramp runs, the horizontal and surface length of each, and the number and length of the level landings required between them. It then checks that layout against the core slope, rise, width, and landing thresholds from the ADA Standards for Accessible Design (2010), and draws a proportionally scaled side-view diagram of the full ramp-and-landing system.
- Solves for the minimum number of runs — Automatically works out how many ramp runs are needed to keep each one at or under the 30 in (760 mm) maximum rise, splitting the total rise evenly between them.
- Adjustable slope ratio — Defaults to the maximum allowed 1:12 slope, but you can enter any gentler ratio — like 1:16 or 1:20 — to see how it changes the ramp's length.
- Landing count and length — Calculates the number of required landings (one more than the number of runs) and checks your landing length against the 60 in (1525 mm) ADA minimum.
- Horizontal run vs. surface length — Shows both the flat horizontal distance the ramp covers and its actual sloped surface length, since the two differ once the ramp isn't perfectly flat.
- Scaled 2D ramp-and-landing profile — Draws a proportionally scaled side-view diagram of every run and landing in sequence, with the total rise and total run labeled.