Wheelchair Ramp Length Calculator

I’ll be honest: I built this because I messed up my own ramp math. Twice.

My front porch step is 7 inches high. I wanted a small ramp for a friend who visits in a wheelchair. I did the back-of-the-envelope thing — "1:12 ratio, so for 7 inches that’s… 7 × 12 = 84 inches. Easy." Then I cut the wood, started measuring, and realised I had made a classic mistake: I measured the horizontal run, not the actual ramp surface length. That extra bit of slope makes a real difference when you're on a budget and cutting plywood.

But the bigger issue was that I didn't trust myself. So I looked for an existing calculator. There are a few on the web, but almost all of them were either ad‑ridden, required me to sign up, or gave a vague "recommended length" without explaining how they got that number. One site asked me for my email just to see the result. That's a joke — I need to know if my 7‑inch step needs a 7‑foot ramp or a 6.5‑foot one, not a marketing email.

So I made a quiet little tool that does one thing: you input the vertical rise in inches (or cm, if you prefer, but let's be real — I used inches) and it outputs the minimum length of ramp run to stay within the 1:12 slope. It also shows you the required length for the slightly stricter 1:16 and 1:20 ratios, which some building codes recommend for more stable accessibility. That extra context is helpful, because sometimes the "ADA compliant" number is actually a minimum, and you might want a gentler slope for safety, especially if the ramp is used by someone with less upper body strength.

The tool itself is deliberately boring: one input, three outputs, and a small table showing the slope ratio so you can double‑check. I also included a diagram (just text and basic shapes) showing what "rise" vs "run" means, because I wanted to avoid the exact confusion I had. No hidden features. No “we’ll email you the results” nonsense.

Why did I make this public? Because I suspect I’m not the only one who has been frustrated by this tiny Geometry problem. It's a 5‑minute calculation, but when you're planning a build, mistakes cost time and money. I'd rather have a simple page that just gives you the number and lets you go back to work.