Ramp Slope (ADA) Calculator
Find the ramp length and angle for a rise using the ADA 1:12 slope. This free online construction & diy calculator runs entirely in your browser — no signup, no data sent anywhere.
Inputs
Results
How It Works (Formula & Method)
The ADA maximum slope for a wheelchair ramp is 1:12 — one inch of rise for every 12 inches of run. Multiply the rise by the ratio to get the horizontal run (the ramp length), and take arctangent(rise ÷ run) for the angle, which stays under about 5° at 1:12.
Worked Example
Below is a worked example using the calculator's default values. The same numbers are pre-filled in the form above so you can press Calculate and see the result without typing anything.
Inputs used:
- Rise / Height (in): 24
- Slope Ratio (run : rise): 12
With these inputs, the calculator computes the metrics shown in the Results panel. Change any value and press Calculate again to see how the result responds — the live widget and the chart both update instantly.
Frequently Asked Questions
What does the Ramp Slope (ADA) Calculator compute?
The Ramp Slope (ADA) Calculator takes 2 input values and returns 3 results. Calculate the ramp length and angle needed for a given rise using a slope ratio, defaulting to the ADA-recommended 1:12 (one foot of ramp per inch of rise).
Is my data sent to a server?
No. The Ramp Slope (ADA) Calculator runs entirely in your browser using static JavaScript. Your inputs are never transmitted to CalculatorHive or any third party, and nothing is stored after you close the page.
Is this calculator free to use?
Yes. Every calculator on CalculatorHive is completely free. There is no signup, no paywall, and no usage limit. The site is supported by display advertising and affiliate partnerships, which are clearly labeled.
How accurate is the result?
The math is mathematically exact for the inputs you provide. Real-world accuracy depends on how accurately your inputs reflect the real situation — defaults are typical values, not guarantees.