ADA Ramp Calculator
Calculate the required ramp length and number of landings for ADA compliance based on the rise height using the 1:12 ratio.
ADA Ramp Requirements
ADA ramp requirements follow the 1:12 slope ratio — for every 1 inch of rise, you need 12 inches (1 foot) of ramp run.
Ramp Length = Rise Height × 12
Number of Landings = Rise Height / 30 inches (rounded up)
ADA ramp standards:
- Maximum slope: 1:12 (8.33% grade)
- Maximum rise per run: 30 inches (76 cm) before a landing is required
- Landing size: At least 60" × 60" (5 ft × 5 ft)
- Minimum width: 36 inches (91 cm) between handrails
- Handrails required if rise exceeds 6 inches
- Edge protection required on both sides
Ramp surface requirements:
- Firm, stable, and slip-resistant
- No abrupt changes in level
- Outdoor ramps should have drainage
Note: Local building codes may have additional requirements beyond ADA minimums. Always check with your local building authority.