What this calculator does
Ramp slope & length works out slope ratio, angle and ramp length for a given rise, checked against the ADA maximum. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaGrade% = 100×rise/run; angle = atan(rise/run); ramp length = √(rise²+run²)
The inputs explained
| Field | What to enter |
|---|---|
| Total rise (vertical) (m) | A number, measured in m. Starts at 0.3. |
| Available run (horizontal) (m) | A number, measured in m. Starts at 3.6. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with total rise (vertical)
Every other input is held at the calculator’s starting values while total rise (vertical) varies. Select any row to load that scenario into the calculator.