Ramp Calculator
Plan a wheelchair or access ramp for your home. Enter the height to climb, pick the slope, width and layout, and get the ramp length, angle and grade, how many runs and landings you need, total footprint, handrail length and an estimated build cost — checked against ADA guidelines, with by-slope and by-rise tables, a ramp profile and a downloadable PDF.
| Slope | Ramp run | With landings | ADA |
|---|---|---|---|
| Enter a rise to compare | |||
| Rise | Ramp run | Runs / landings | With landings |
|---|---|---|---|
| Enter a rise to compare | |||
How to use the ramp calculator
Four quick steps turn the height of a step, porch or doorway into ramp length, landings, footprint, handrails and cost — with an ADA check, by-slope and by-rise tables, a profile chart and a downloadable report.
Measure the rise
Enter the total height in inches from the ground up to the top of the porch, deck or door threshold.
Pick the slope
Choose 1:12 (ADA maximum), 1:16 or 1:20 for an easier push, or 1:8 for tight residential spaces.
Set width, landings & layout
Enter the clear width and landing length, then choose a straight, L-shaped or switchback layout and a cost per sq ft.
Read results & save a PDF
Get the run, landings, total length, footprint, handrails, ADA check and cost — then download a report.
How ramp length is calculated
A ramp’s slope is written as rise : run, so the run is simply the rise times the ratio. Landings, handrails and area follow from that. Here is the exact math the calculator runs.
Worked example — 24″ rise, 1:12 slope, 48″ wide, 60″ landings, straight layout, $40 per sq ft
Run: 24 × 12 = 288" = 24 ft · Runs: 24 ÷ 30 → 1 run, 2 landings · Sloped length: ≈ 24' 1"
Total length: 288 + 2 × 60 = 408" = 34 ft · Footprint: 34 × 4 ft · Grade: 8.33% (4.76°)
Handrails: 2 × (289 + 24) ≈ 52.2 ft · Area: (289 + 120) × 48 ÷ 144 ≈ 136 sq ft · Cost: 136 × $40 ≈ $5,453
≈ a 24 ft ramp, 34 ft long with landings — meets ADA, needs handrails on both sides, and runs about $5,450 installed.
Ramp length reference charts
Handy lookups for how slope changes ramp length, how much ramp each rise needs, and how layout changes the footprint.
| Slope | Ramp run | With landings | ADA |
|---|---|---|---|
| 1:20 · 2.9° (5%) | 40′ 0″ | 50′ 0″ | OK |
| 1:16 · 3.6° (6.25%) | 32′ 0″ | 42′ 0″ | OK |
| 1:12 · 4.8° (8.33%) | 24′ 0″ | 34′ 0″ | OK |
| 1:8 · 7.1° (12.5%) | 16′ 0″ | 26′ 0″ | Too steep |
1:12 is the ADA maximum. 1:8 is allowed by residential codes only where space is tight, and most wheelchair users will need help on it.
| Rise | Ramp run | Runs / landings | With landings |
|---|---|---|---|
| 6″ | 6′ 0″ | 1 / 2 | 16′ 0″ |
| 12″ | 12′ 0″ | 1 / 2 | 22′ 0″ |
| 18″ | 18′ 0″ | 1 / 2 | 28′ 0″ |
| 24″ | 24′ 0″ | 1 / 2 | 34′ 0″ |
| 30″ | 30′ 0″ | 1 / 2 | 40′ 0″ |
| 36″ | 36′ 0″ | 2 / 3 | 51′ 0″ |
| 48″ | 48′ 0″ | 2 / 3 | 63′ 0″ |
At 1:12 you need 1 ft of ramp for every inch of rise. Above 30″ the ramp splits into runs with a level landing between them.
| Layout | Shape | Approx. footprint | Best for |
|---|---|---|---|
| Straight | One line | 63′ 0″ × 4′ 0″ | Long, open frontage |
| L-shaped | 90° turn on a landing | 34′ 0″ × 33′ 0″ | Wrapping a corner |
| Switchback | 180° turn on a landing | 34′ 0″ × 8′ 4″ | Tall rises in tight spaces |
Footprints are approximate. Turning landings should be at least 60 × 60 inches.
What the ramp calculator gives you
One rise measurement gives you a full ramp plan — length, layout, safety features and budget.
Ramp rules at a glance
Who uses a ramp calculator
Whether you’re planning for a family member or building for a client, the same calculator lays out a safe ramp.
Needs a wheelchair ramp to the front door and wants to know how long it will be and what it will cost.
- Measure the rise
- Use 1:12 or gentler
- Check the footprint
Designing a code-compliant ramp and needs runs, landings, handrail lengths and a quote figure.
- Run the ADA check
- Pick an L or switchback
- Share the PDF
Building a short wood ramp over a step or two and wants the length and materials budget.
- Enter $15/sq ft for DIY
- Compare slopes
- Check permit rules
Tips for a safe, usable ramp
A ramp that meets the numbers is a good start — these habits make it safe in every season.
Ramp calculator FAQ
Quick answers about ramp length, ADA slope, landings, width, handrails and cost.
At the ADA maximum slope of 1:12, you need 1 foot of ramp for every inch of rise. A 24 inch rise needs a 24 ft ramp.
Add the level landings at the top and bottom — with 60 inch landings that 24 ft ramp is 34 ft long overall.
The 2010 ADA Standards allow a maximum slope of 1:12 — 1 inch of rise for every 12 inches of run, which is an 8.33% grade or about 4.76°.
Gentler slopes of 1:16 (6.25%) or 1:20 (5%) are easier to push up unassisted but need a longer ramp: 32 ft or 40 ft for a 24 inch rise.
Residential codes (IRC) allow up to 1:8 only where space is tight. A 24 inch rise at 1:8 needs just 16 ft of ramp.
That is steeper than the ADA maximum, so most wheelchair users will need help on it. Use 1:12 or gentler whenever you have room.
Each ramp run can climb at most 30 inches, so you need a level landing at the top, at the bottom and between runs. Landings must be at least 60 inches long.
A 36 inch rise at 1:12 becomes 2 runs of 18 ft with 3 landings — 51 ft long with 60 inch landings.
The ADA minimum is 36 inches of clear width between handrails.
42 to 48 inches is more comfortable and fits power chairs and a helper walking alongside. Turning landings should be at least 60 × 60 inches.
Yes, when the rise is more than 6 inches. ADA calls for handrails on both sides, 34 to 38 inches high, extending 12 inches past the top and bottom of each run.
For a 24 inch rise at 1:12, that is about 52.2 ft of handrail in total. Add edge protection so wheels can’t roll off the side.
Use an L-shaped or switchback layout that turns on a level landing. For a 48 inch rise at 1:12, a straight ramp needs about 63 × 4 ft.
An L-shaped ramp fits in about 34 × 33 ft around a corner, and a switchback folds into about 34 × 8 ft 4 in.
Treated-wood ramps often cost about $25 to $60 per sq ft installed, and aluminum modular or concrete ramps cost more. A 24 inch rise ramp with landings is about 136 sq ft, or about $5,453 at $40 per sq ft.
DIY materials run about $15 per sq ft, or roughly $2,045 for the same ramp. Many states, VA programs and nonprofits help pay for home access ramps.
Planning aid only — check your local code. This calculator works in US units (inches, feet) and is based on the 2010 ADA Standards: maximum slope 1:12, at most 30 inches of rise per run, landings at least 60 inches long, 36 inches minimum clear width and handrails on both sides above 6 inches of rise. Residential codes (IRC) allow up to 1:8 only where space is tight. Footprints and costs are approximate — check your local building code and permit rules, and have a contractor confirm footings, railings and edge protection.