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ADA Concrete Ramp Calculator

Calculate concrete volume and verify 1:12 slope compliance for commercial ADA wheelchair ramps.

Ramp dimensions

ADA requires a maximum 1:12 slope — for every 1 inch of rise, the ramp must extend at least 12 inches horizontally.

Result

72 in required run

(6.0 ft) at 1:12 slope for 6 in rise

Total cubic yards
0.33 yd³
8.8 ft³ with 10% waste
80 lb bags needed
15 bags
Rounded up at 0.60 ft³ per bag

Commercial and public ADA wheelchair ramps must meet a maximum 1:12 slope — one inch of rise for every twelve inches of run. Enter your vertical rise, ramp width, and slab thickness to get the required run length, cubic yards of concrete, and 80 lb bag count with 10% waste included.

Frequently asked questions

What is the ADA maximum ramp slope?
The ADA Accessibility Guidelines specify a maximum slope of 1:12 for public ramps — 1 inch of vertical rise requires at least 12 inches of horizontal run.
How thick should an ADA ramp slab be?
Most commercial ramps use 4–6 inches of reinforced concrete. Check local building codes and your engineer's spec for load requirements.
How many 80 lb concrete bags do I need?
Divide your volume in cubic feet by the bag yield (80 lb ≈ 0.60 ft³ per bag), add your waste factor, then round up. Our calculator does this live — e.g. a 12×10×4 in slab with 10% waste needs 74 bags.

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