1. What is Soil Grade?

Soil grade (or slope percentage) is a measure of the steepness of a slope, calculated as the ratio of vertical rise to horizontal run, expressed as a percentage.

2. How Does the Calculator Work?

The calculator uses the grade formula:

Where:

• \( Rise \) — Vertical change in elevation (feet)
• \( Run \) — Horizontal distance (feet)

Explanation: The formula calculates what percentage of the horizontal distance the elevation changes.

3. Importance of Grade Calculation

Details: Knowing soil grade is essential for construction, landscaping, drainage planning, and erosion control. Different plants and structures have different grade requirements.

4. Using the Calculator

Tips: Enter both rise and run in feet. Both values must be positive numbers. The result will be shown as a percentage.

5. Frequently Asked Questions (FAQ)

Q1: What's considered a steep grade?
A: Generally, grades above 25% are considered steep, while grades above 50% are very steep and may require special engineering.

Q2: How does grade relate to angle in degrees?
A: Grade percentage = tan(angle) × 100. For example, a 45° angle equals a 100% grade.

Q3: What's the maximum recommended grade for driveways?
A: Typically 15-20% maximum, with 12% being more comfortable for regular use.

Q4: 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.

Q5: What grade is best for drainage?
A: A minimum of 2% (2 feet drop per 100 feet) is recommended for proper drainage away from structures.