1. What is Percent Elevation Grade?

Percent grade is a measure of slope steepness expressed as a percentage. It represents the ratio of vertical rise to horizontal run multiplied by 100. This measurement is commonly used in engineering, construction, and outdoor activities to describe incline steepness.

2. How Does the Calculator Work?

The calculator uses the trigonometric formula:

Where:

• \( \theta \) — Angle of elevation in degrees
• \( \tan \) — Tangent trigonometric function

Explanation: The tangent of the angle gives the ratio of rise over run, and multiplying by 100 converts this ratio to a percentage.

3. Practical Applications

Details: Percent grade is used in road design (maximum grades for highways), wheelchair ramp construction (typically 8.33% max), hiking trail classification, and civil engineering projects.

4. Using the Calculator

Tips: Enter the angle in degrees (0-90). The calculator will compute the corresponding percent grade. For example, a 45° angle equals 100% grade.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between percent grade and degrees?
A: Degrees measure the angle directly, while percent grade measures the tangent of that angle multiplied by 100.

Q2: What does 100% grade mean?
A: 100% grade corresponds to a 45° angle, where the vertical rise equals the horizontal run (1:1 slope).

Q3: What's the maximum possible grade?
A: Theoretically approaches infinity as angle approaches 90° (vertical). Practically, grades above 100% are extremely steep.

Q4: How does this relate to slope ratio (e.g., 1:4)?
A: A 1:4 slope (1 unit rise per 4 units run) equals 25% grade (1/4 × 100).

Q5: Why use percent grade instead of angle?
A: Percent grade is often more intuitive for practical applications like construction and transportation planning.