Wheelchair Ramp Slope Calculator
A wheelchair ramp slope calculator helps determine the safe and ADA-compliant slope ratio for wheelchair ramps. It calculates the required ramp length based on vertical rise and ensures the slope percentage meets accessibility standards (typically 1:12 slope). Proper slope calculation is crucial for creating safe, accessible environments for wheelchair users and individuals with mobility challenges.
Calculation Formula
Slope ratio = Rise ÷ Run (then converted to percentage). Maximum allowable slope: 1:12 ratio (8.33% slope). Formula: Slope Percentage = (Vertical Rise / Horizontal Run) × 100. ADA requires at least 1 foot (12 inches) of ramp length for every 1 inch of vertical rise.
How to Use
1. Measure vertical height (rise) from ground to entrance. 2. Measure available horizontal space (run). 3. Input measurements. 4. Click calculate. The tool will show slope percentage and compliance status. If slope exceeds 8.33%, adjust measurements or consider switchback ramps.
Calculation Process
The calculator divides rise by run to get slope ratio, multiplies by 100 for percentage. It checks against ADA's 8.33% maximum (1:12 ratio). Example: 30" rise needs 360" run (30×12). Results show if compliant and required ramp length.
1. What is maximum slope for wheelchair ramps?
The maximum ADA-compliant slope is 1:12 ratio (8.33% slope), meaning 1 inch rise requires 12 inches of ramp length. Steeper slopes can be dangerous for wheelchair users. Commercial ramps must follow this standard, while residential ramps can sometimes use 2:12 ratio (16.67%) for existing structures.
2. How to measure ramp slope properly?
Measure vertical rise from ground to landing and horizontal run from base to top. Use level for accurate measurements. For existing ramps, measure slope angle with digital level or calculate using rise/run ratio. Always ensure measurements account for proper landing space at top and bottom.
3. Can I use this calculator for commercial ramps?
Yes, this calculator follows ADA standards required for commercial and public access ramps. Commercial ramps must maintain 1:12 slope ratio with proper landings, handrails, and width. Always consult local building codes as some areas may have additional requirements.