1. What is Percent Slope?

Percent slope is a measure of the steepness or incline of a surface, expressed as a percentage. It represents the ratio of vertical rise to horizontal run, multiplied by 100. This calculation is commonly used in drainage planning, construction, and civil engineering projects.

2. How Does the Calculator Work?

The calculator uses the percent slope formula:

Where:

• \( Rise \) — Vertical height difference (in feet)
• \( Run \) — Horizontal distance (in feet)

Explanation: The formula calculates the slope as a percentage by dividing the vertical rise by the horizontal run and multiplying by 100 to convert to a percentage.

3. Importance of Percent Slope Calculation

Details: Accurate slope calculation is crucial for proper drainage design, road construction, ramp design, and ensuring water flows away from structures to prevent flooding and water damage.

4. Using the Calculator

Tips: Enter rise and run values in feet. Both values must be positive numbers, and run must be greater than zero. The calculator will compute the percent slope.

5. Frequently Asked Questions (FAQ)

Q1: What is a good percent slope for drainage?
A: For effective drainage, a minimum slope of 1-2% is typically recommended to ensure proper water flow away from structures.

Q2: How does percent slope relate to angle in degrees?
A: Percent slope = tan(angle) × 100. A 45-degree angle equals a 100% slope.

Q3: What's the difference between percent slope and ratio slope?
A: Percent slope expresses the ratio as a percentage (e.g., 5%), while ratio slope expresses it as a ratio (e.g., 1:20).

Q4: Can I use different units for rise and run?
A: Yes, as long as both measurements use the same units (both in feet, both in meters, etc.), the calculation will be accurate.

Q5: What is considered a steep slope?
A: Generally, slopes above 25-30% are considered steep and may require special construction considerations.