1. What is a Slope Percentage Calculator?

Definition: This calculator determines the slope percentage based on the vertical rise and horizontal run measurements.

Purpose: It helps engineers, builders, and landscapers quantify the steepness of a slope for construction, drainage, or accessibility planning.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Rise — Vertical height difference (meters)
• Run — Horizontal distance (meters)

Explanation: The ratio of vertical change to horizontal distance is converted to a percentage by multiplying by 100.

3. Importance of Slope Percentage

Details: Slope percentage is crucial for determining wheelchair accessibility (max 8.33%), roof pitches, road grades, and proper drainage (minimum 2% recommended).

4. Using the Calculator

Tips: Enter both rise and run in meters (or consistent units). The calculator automatically converts the ratio to percentage.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between slope percentage and slope angle?
A: Percentage is (rise/run)×100 while angle is arctan(rise/run) in degrees. 100% slope = 45° angle.

Q2: What's considered a steep slope?
A: Over 25% is steep, 10-25% is moderate, under 10% is gentle. Building codes often restrict construction on slopes >30%.

Q3: How do I measure rise and run in the field?
A: Use a level and measuring tape, or modern tools like laser levels or smartphone apps with inclinometers.

Q4: Can I use different units?
A: Yes, as long as rise and run use the same units (feet, meters, etc.), the percentage result will be correct.

Q5: What slope percentage is ADA compliant?
A: The ADA recommends maximum 8.33% slope (1:12 ratio) for wheelchair ramps.