Ten inches: an 8 ft ramp falls short
A 10 inch rise is where a ramp that looks long enough can turn out too steep. An 8 ft ramp over this height is 1:9.6, a 10.4% slope, against the 8.3% of 1:12. The full 10 ft is needed.
At 1:16 the ramp is 13.33 ft and at 1:20 it is 16.67 ft, so the gentlest slope adds 6.67 ft. With the top landing and the clear space at the bottom, the 1:20 ramp needs 26.67 ft from end to end against 20 ft at 1:12.
10 inch rise at each slope
| Slope | Ramp length (run) | Along the surface | Percent | Angle | Runs | Footprint with landings |
|---|---|---|---|---|---|---|
| 1:12 (ADA maximum) | 10 ft | 10.03 ft | 8.3% | 4.8° | 1 | 15 ft |
| 1:16 | 13.33 ft | 13.36 ft | 6.3% | 3.6° | 1 | 18.33 ft |
| 1:20 | 16.67 ft | 16.69 ft | 5.0% | 2.9° | 1 | 21.67 ft |
The footprint adds a 5 ft landing at the top. Allow 5 ft of clear, level space at the bottom too: with it the 1:12 ramp needs 20 ft from end to end. That bottom space is not in the concrete estimate below.
Is my ramp too steep for 10 inches?
Slope is rise ÷ run. For a 10 inch rise, a ramp shorter than 10 ft is steeper than 1:12:
| Ramp length | Slope | Percent | Angle | Within 1:12? |
|---|---|---|---|---|
| 6 ft | 1:7.2 | 13.9% | 7.9° | No, 4 ft too short |
| 8 ft | 1:9.6 | 10.4% | 5.9° | No, 2 ft too short |
| 10 ft | 1:12 | 8.3% | 4.8° | Yes |
| 14 ft | 1:16.8 | 6.0% | 3.4° | Yes |
Materials for the 10 ft ramp
A wood ramp 10 ft long and 36 inches wide takes 22 rows of 5/4×6 deck boards laid across it, 73 lineal feet with 10% extra, on 4 joists per run at 16 inch centers (45 lineal feet). The 4 inch concrete for the top landing is 0.34 cubic yards, about 16 bags of 80 lb mix. Built 48 inches wide, the decking rises to 97 lineal feet on the same 4 joists per run. Handrails on both sides, with a 12 inch level extension at the top and bottom of the run, come to 25 lineal feet of rail. Posts, brackets and footings are not in these figures.
Ramp length for nearby rises
| Rise | 1:12 | 1:16 | 1:20 | Runs | Footprint at 1:12 |
|---|---|---|---|---|---|
| 6 in | 6 ft | 8 ft | 10 ft | 1 | 11 ft |
| 8 in | 8 ft | 10.67 ft | 13.33 ft | 1 | 13 ft |
| 10 in | 10 ft | 13.33 ft | 16.67 ft | 1 | 15 ft |
| 12 in | 12 ft | 16 ft | 20 ft | 1 | 17 ft |
| 14 in | 14 ft | 18.67 ft | 23.33 ft | 1 | 19 ft |
Coming down steps instead of a measured height? See a ramp for 1 step or a ramp for 2 steps, or read the ramp length and slope guide.
Want to change anything else? The calculator above is the full Wheelchair Ramp Calculator: edit any number and the results update instantly.
Tools & materials for this project
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Frequently asked questions
How long does a wheelchair ramp need to be for a 10 inch rise?
10 ft at the 1:12 maximum slope, because every inch of rise needs 12 inches of ramp. With the landings it takes up 15 ft. At 1:16 the ramp is 13.33 ft and at 1:20 it is 16.67 ft.
Is an 8 foot ramp long enough for a 10 inch rise?
No. 10 inches over 8 feet is 1:9.6, a 10.4% slope at 5.9°, steeper than the 1:12 maximum. It is 2 ft too short: a 10 inch rise needs 10 ft.
What is the slope of a 10 ft ramp with a 10 inch rise?
1:12, which is 8.3% or 4.8 degrees. Divide the rise by the run in the same unit: 10 ÷ 120 inches = 0.0833.
Related sizes and guides
Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.