1. What is Slope Ratio?

Slope Ratio represents the relationship between horizontal distance (run) and vertical distance (rise) in construction, drainage, and civil engineering applications. It is commonly expressed as Run:Rise ratio.

2. How Does the Calculator Work?

The calculator uses the slope ratio formula:

Where:

• \( Run \) — Horizontal distance (any units)
• \( Rise \) — Vertical distance (same units as run)
• \( Slope\ Ratio \) — Dimensionless ratio of run to rise

Explanation: The ratio indicates how many units of horizontal distance correspond to one unit of vertical distance. For example, a 4:1 ratio means 4 units horizontal for every 1 unit vertical.

3. Importance of Slope Ratio Calculation

Details: Accurate slope ratio calculation is essential for proper drainage design, road construction, ramp installations, and ensuring compliance with building codes and accessibility standards.

4. Using the Calculator

Tips: Enter both run and rise values in the same units. Values must be positive numbers greater than zero. The calculator will output the ratio in the format "1:X" where X represents the slope ratio.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between slope ratio and slope percentage?
A: Slope ratio (e.g., 4:1) represents the horizontal to vertical relationship, while slope percentage is the vertical rise divided by horizontal run multiplied by 100.

Q2: What are common slope ratios used in construction?
A: Common ratios include 2:1 for steep slopes, 3:1 for moderate slopes, and 4:1 or 5:1 for gentle slopes and accessible ramps.

Q3: How do I convert slope ratio to degrees?
A: Use the formula: angle = arctan(rise/run). For example, a 4:1 ratio equals arctan(1/4) ≈ 14.04 degrees.

Q4: What is the maximum slope ratio for wheelchair ramps?
A: ADA guidelines typically require a maximum slope of 1:12 (8.33%) for wheelchair ramps.

Q5: Can I use different units for run and rise?
A: No, both values must use the same units since the ratio is dimensionless and unitless.