Ramp Length Guide
Rescue Supply · Ramp Buying Guide
Ramp Length Guide
How long should a wheelchair ramp be? Measure your rise, pick your slope, and get the exact length — with layouts for tight spaces and a plain-English guide to the ADA rules for homes and businesses.
Interactive Tool
Ramp Length Calculator
Drag the sliders and watch your ramp size itself. Start with your rise — the height from the ground to your door threshold.
≈ 3 typical steps
1:12 is the steepest slope accessibility standards recommend. Gentler is easier to climb, but longer.
Measure out from the door along the path the ramp would take.
That is 252 inches at a 1:12 slope (8.3% grade · 4.8°).
Minimums for planning — a specialist confirms the final layout for your home, local codes, and door swing.
The Basics
How long does your wheelchair ramp need to be?
It starts with one measurement: the rise — the total vertical height the ramp has to climb, from the ground to the top of the step, porch, or threshold. Once you know the rise, a single rule gives you the minimum ramp length.
- Start with the total rise. Measure from the ground or landing where the ramp will end up to the landing surface at the top — one number drives every length in this guide.
- Apply the 1:12 rule. Allow 12 inches of ramp run for every 1 inch of rise — at least 1 foot of ramp for each inch of climb.
- Gentler slopes take more length. A 1:16 or 1:20 slope is easier to climb, but the ramp must be longer to cover the same rise.
- Landings add to the footprint. No single run can rise more than 30 inches, so taller climbs become multiple runs joined by flat landings — and those landings take space on top of the sloped length.
- Measure the space you have. Knowing your straight-line room before you choose a layout tells you whether a straight ramp fits or a switchback is the better plan.
Step One
How to measure your rise
You only need one number, but it has to be the right one. A wrong rise means a wrong ramp length, so measure before you shop.
- Start at the ground where the bottom of the ramp will sit. If the ground slopes away from the house, measure from that lower point — the ramp has to reach it.
- Measure straight up from that point to the top of the door threshold — the surface the wheelchair actually rolls onto. Include any raised lip or sill at the door.
- That single measurement is the total rise for all of your steps combined. Do not measure one step and multiply: step heights vary, and small errors turn into a ramp that is feet too short.
A tape measure and a second pair of hands make this easier. Write the number down in inches — every table below uses it.
The Rule
The 1:12 rule
Accessibility standards size ramps at a slope of 1:12 — one inch of rise for every 12 inches of ramp run.
Put another way: you need at least 1 foot of ramp for every 1 inch of rise. A 6-inch step needs at least a 6-foot ramp; a 24-inch porch needs at least a 24-foot ramp.
1:12 is the steepest slope the standards recommend. Many people choose a gentler 1:16 slope instead — especially for power chairs and scooters, and for manual wheelchair users who propel themselves — because it is noticeably easier to climb.
Reference Table
Rise-to-length table
Find your rise in the left column. The 1:12 columns give the minimum length; the last column shows the length at the gentler 1:16 slope.
| Rise (inches) | Minimum length at 1:12 (inches) | Minimum length at 1:12 (feet) | Gentler length at 1:16 (feet) |
|---|---|---|---|
| 2 | 24 | 2 | 2.7 |
| 3 | 36 | 3 | 4 |
| 4 | 48 | 4 | 5.3 |
| 5 | 60 | 5 | 6.7 |
| 6 | 72 | 6 | 8 |
| 8 | 96 | 8 | 10.7 |
| 10 | 120 | 10 | 13.3 |
| 12 | 144 | 12 | 16 |
| 14 | 168 | 14 | 18.7 |
| 16 | 192 | 16 | 21.3 |
| 18 | 216 | 18 | 24 |
| 20 | 240 | 20 | 26.7 |
| 22 | 264 | 22 | 29.3 |
| 24 | 288 | 24 | 32 |
| 26 | 312 | 26 | 34.7 |
| 28 | 336 | 28 | 37.3 |
| 30 | 360 | 30 | 40 |
Quick Estimate
Starting from steps?
Most people count steps, not inches. A typical step is about 7 inches high, so you can estimate your rise — and your ramp length — from the step count.
| Steps | Typical total rise | Minimum ramp length (1:12) |
|---|---|---|
| 1 | about 7 inches | about 7 feet |
| 2 | about 14 inches | about 14 feet |
| 3 | about 21 inches | about 21 feet |
| 4 | about 28 inches | about 28 feet |
Use this only for a first estimate. Real step heights run from about 6 to 8 inches, so two homes with "three steps" can need ramps several feet apart in length. Measure your actual rise before you order.
Commercial vs. Residential
The law follows the building, not the ramp
The ADA is a civil rights law: it reaches places the public uses. A private home sits outside it entirely. The difference is not the ramp — it is whether the law applies to the building.
Commercial ramps
Hospitals, clinics, schools, offices, stores, hotels, government buildings — anything open to the public must meet the 2010 ADA Standards:
- 1:12 maximum running slope; cross slope no more than 1:48
- 30 inches maximum rise per run, then a flat landing
- 36 inches minimum clear width between handrails
- Handrails on both sides when the rise exceeds 6 inches
- Level landings at the top and bottom of every run — 60×60 inches where the ramp turns
- Edge protection so casters can't slip off; firm, slip-resistant surfaces
Most commercial installations are built from modular ramp systems configured to the site.
Existing buildings get one narrow exception for renovations: 1:10 for rises up to 6 inches, 1:8 up to 3 inches. New construction gets none.
Residential ramps
A private single-family home is explicitly not covered by the ADA. There is no federal slope law for your own front porch — the homeowner decides.
- 1:12 remains the recommended standard — because it is the slope the ramp is actually usable at, not because it is required
- Steeper portable or vehicle ramps are common for assisted use and loading — with the trade-off in safety and independence
- Local permits still apply for permanent structures in many cities — check your building department
- Multifamily housing is different: apartment common areas and leasing offices are ADA-covered; the units fall under the Fair Housing Act
Running a business open to the public out of a home (for example, a daycare) can bring that space under the ADA too.
What does "ADA compliant" actually mean? No government body certifies a ramp product. Compliance is a property of the installation — slope as actually built, landings, rails, width, surface, and door clearance. A ramp "built to ADA specifications" only complies once it is installed to them; a great ramp poured at 1:10 in a new commercial building still fails.
Why these numbers? They come from wheelchair ergonomics: 1:12 is roughly the steepest slope a typical manual wheelchair user can climb — and descend — under their own control. The 30-inch cap forces rest landings before fatigue becomes a fall. Landings give room to stop and swing doors; handrails give pulling power and balance; edge protection keeps small front casters from sliding off. It is the physics of independent use, written into law.
One More Limit
The 30-inch limit for a single run
Thirty inches is the maximum rise for a single ramp run. More than that, and the ramp must be built in two or more runs with a flat landing between them — which makes the total footprint longer than the table alone suggests. Even at exactly 30 inches of rise, the minimum run is 30 feet, so plan the space carefully.
- 30 inches is the cap for one run. No single ramp run may rise more than 30 inches (ADA §405.6).
- Taller entrances use more runs. Anything higher is built as multiple runs joined by level landings.
- Landings are at least 60 inches long — and 60×60 inches where the ramp turns.
- Handrails are required on both sides when a run rises more than 6 inches.
- The limit is per run, not per ramp. A ramp can climb far more than 30 inches in total — it just has to rest on a landing between runs.
See It Work
Worked examples
Three real situations, with the math spelled out.
A single 6-inch step
Rise = 6 inches. Minimum length = 6 × 12 = 72 inches. = 6 feet
A shorter ramp would be steeper than 1:12 and noticeably harder to climb, especially in a manual wheelchair.
A 24-inch porch rise
Rise = 24 inches. Minimum length = 24 × 12 = 288 inches. = 24 feet
Long for most yards, but under the 30-inch single-run limit — or split into two runs with a landing if space is tight. At 1:16 it would be 32 feet.
A 30-inch deck rise
Rise = 30 inches. Minimum length = 30 × 12 = 360 inches. = 30 feet
The tallest rise one run can handle. One more inch and the ramp must be split into multiple runs with a landing.
Tight Spaces
What if you don't have room for a straight ramp?
This is the most common problem the table creates: your rise may call for 20-plus feet of ramp, but your yard is not that long in a straight line. The fix is to fold the ramp — the total sloped run stays the same, it just changes direction on flat landings.
L-shaped ramp
Turns 90 degrees on a landing, so the run can follow the house instead of crossing the whole yard — ideal when the walkway sits to one side of the door.
Switchback ramp
Turns 180 degrees on a landing and runs back alongside itself — the layout of choice for taller rises in tight spaces.
A landing where the ramp changes direction should be at least 5 feet by 5 feet, so the chair has room to turn. Leave level space at the top as well: enough room in front of the door for the chair to sit flat while the door opens.
Example: a 24-inch rise needs 24 feet of run. Built as two 12-foot runs joined by a 5-by-5-foot landing, that same ramp reaches roughly 17 feet out from the door instead of 24 — and the slope stays a safe 1:12 the whole way. A specialist can lay out the exact footprint for your space.
Folded layouts like these are built from modular wheelchair ramp systems — sections and flat platforms configured piece by piece to fit the space you actually have.
Wisdom
Good rules of thumb
When in doubt, go longer
A ramp longer than the minimum has a gentler slope — and a gentler slope is easier and safer for the person in the chair and for anyone assisting.
Short portables are for small jobs
Portable ramps are made for thresholds and single low steps. If the table says you need 14 feet, a 5-foot portable ramp is not a shortcut — it will be far too steep to use safely.
Minimums, not finished designs
These figures are minimums for planning. Local codes, permits, and individual needs vary — treat them as a starting point, not a final design.
Shop by Rise
Ramps sized to your rise
Once you know the length you need, match it to a ramp type. These are the ramps our customers use most often for each situation.
Thresholds and small lips
For door sills and rises of a few inches, a threshold ramp is often all you need. See the National Ramp Approach Series rubber threshold ramp and the full threshold ramps collection.
One or two steps
Portable ramps cover short runs and travel. Compare the Roll-A-Ramp 36" roll-up ramp and other portable ramps, and check that the length still meets the 1:12 slope.
Porches, decks, and long runs
Modular aluminum systems add sections and platforms to reach any length. Start with the Rampit USA 36" Independence Series or the wider 48" Independence Series, or browse wheelchair ramps for homes.
Building a ramp for a business, school, or public entrance? Commercial systems such as the Rampit USA 48" United Series are built for heavier traffic. Our commercial modular ramp guide covers layouts and quoting, and the modular wheelchair ramps collection shows every system we carry.
Quick Answers
Quick answers to the questions we hear most
Do landings count toward the lengths in the table?
No. The table gives the sloped run only. Landings are flat and take additional space on top of those numbers — plan your footprint accordingly.
My rise falls between two rows of the table. Which length do I use?
Round up. Use the next row's length so your slope stays at or gentler than 1:12.
How wide does the ramp need to be?
The accessibility standard is at least 36 inches of clear width. Wider chairs and scooters may need more — it is worth confirming against your chair before you buy.
Do I need handrails?
Handrails are generally recommended once a ramp climbs more than 6 inches of rise or runs longer than 6 feet — which covers most ramps for porches and decks.
What about ramp types, materials, and cost?
Those depend on your rise, your space, and whether the ramp is temporary or permanent. Our Wheelchair Ramp Buying Guide walks through the options, and a quote prices your exact layout.
Keep Reading
More guides from Rescue Supply
Ready When You Are
Not sure which ramp fits your rise?
Tell us your total rise and the space you have to work with, and a ramp specialist can recommend the right length and layout for your home or project — sized correctly before you buy.