1. What Is Grade Percentage?

Grade percentage represents the steepness of a slope expressed as a percentage. It is commonly used in civil engineering, road construction, landscaping, and various other fields to quantify the incline or decline of a surface.

2. How Does The Calculator Work?

The calculator uses the grade percentage formula:

Where:

• \( \text{Rise} \) — Vertical height change (feet)
• \( \text{Run} \) — Horizontal distance (feet)

Explanation: The formula calculates the ratio of vertical rise to horizontal run, then multiplies by 100 to convert to percentage format.

3. Importance Of Grade Percentage Calculation

Details: Accurate grade percentage calculation is essential for road design, drainage planning, wheelchair accessibility compliance, construction projects, and ensuring safe slopes for various applications.

4. Using The Calculator

Tips: Enter rise and run values in feet. Both values must be positive numbers greater than zero. The calculator will compute the grade percentage automatically.

5. Frequently Asked Questions (FAQ)

Q1: What Is Considered A Steep Grade?
A: Generally, grades above 10% are considered steep, while grades above 20% are very steep and may require special considerations for construction and accessibility.

Q2: How Does Grade Percentage Relate To Slope Angle?
A: Grade percentage = tan(θ) × 100, where θ is the slope angle in degrees. For example, a 45° slope equals 100% grade.

Q3: What Is The Maximum Grade For ADA Compliance?
A: The Americans with Disabilities Act requires wheelchair ramps to have a maximum slope of 1:12, which equals approximately 8.33% grade.

Q4: Can I Use Different Units For Rise And Run?
A: Yes, as long as both rise and run use the same units (feet, meters, inches), the grade percentage calculation remains valid.

Q5: What Is A Typical Road Grade?
A: Most highways are designed with grades less than 6%, while mountain roads may have grades up to 10-12% in certain sections.