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ADA Ramp Length Formula:
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The ADA (Americans with Disabilities Act) ramp length calculation determines the minimum required length for a ramp based on the vertical rise, using the standard 1:12 slope ratio for accessibility compliance.
The calculator uses the ADA standard formula:
Where:
Explanation: The 1:12 slope ratio means for every 1 inch of vertical rise, you need 12 inches (1 foot) of horizontal run. The calculation converts rise in inches to required ramp length in feet.
Details: ADA-compliant ramps ensure safe and accessible routes for individuals with mobility impairments, including wheelchair users. Proper slope ratios prevent accidents and provide dignified access to buildings and facilities.
Tips: Enter the vertical rise in inches. The calculator will provide the minimum required ramp length in feet according to ADA 1:12 slope standards. Rise must be a positive number.
Q1: What is the ADA 1:12 slope ratio?
A: For every 1 inch of vertical rise, the ramp must extend 12 inches horizontally. This creates a gentle 4.76-degree slope suitable for wheelchair access.
Q2: Are there exceptions to the 1:12 ratio?
A: Yes, for existing buildings where space is limited, steeper slopes up to 1:8 may be permitted for very short rises, but 1:12 is the standard for new construction.
Q3: What is the maximum rise for a single ramp run?
A: ADA requires landings for every 30 inches of rise. For longer elevations, multiple ramp sections with intermediate landings are needed.
Q4: Do I need handrails for ADA ramps?
A: Handrails are required on both sides if the ramp rise exceeds 6 inches or the horizontal projection exceeds 72 inches.
Q5: What about ramp width requirements?
A: ADA requires a minimum clear width of 36 inches between handrails for wheelchair passage.