Slope Angle Calculator
Use this Slope Angle Calculator to estimate volume for the Slope Angle Calculator search intent. Use this elevation grade calculator to convert between rise, run, grade percentage, and slope angle. It is handy for grading, drainage, driveway planning, and any project where you need to understand slope quickly.
Result
--
What This Slope Angle Calculator Helps You Do
Use this elevation grade calculator to convert between rise, run, grade percentage, and slope angle. It is handy for grading, drainage, driveway planning, and any project where you need to understand slope quickly.
How to Slope Angle Calculator
- Choose what you know - Decide whether you know rise and run, rise and grade, or another pair of values.
- Enter the values - Fill in the known measurements and use the correct units for your project site.
- Pick the solve-for mode - Choose grade, rise, run, or angle depending on the value you want to find.
- Use the slope result - Apply the result to drainage, grading, road, or ramp planning, then verify it against local requirements.
Slope Angle Calculator Formula
| Symbol | Definition | Unit |
|---|---|---|
| Rise | Vertical change in elevation | ft |
| Run | Horizontal distance | ft |
| Grade | Slope as a percentage | % |
| Angle | Slope angle | deg |
Working Examples for Slope Angle Calculator
- Rise: 5 ft
- Run: 100 ft
Result: Grade = 5 %. Angle = 2.86 deg.
A driveway with 5 feet of rise over 100 feet of run has a gentle 5% slope.
- Rise: 2 ft
- Run: 40 ft
Result: Grade = 5 %. Angle = 2.86 deg.
The slope is the same ratio as the driveway example, so the grade is still 5%.
- Grade: 8 %
- Run: 50 ft
Result: Rise = 4 ft.
An 8% grade over 50 feet creates about 4 feet of vertical change.
- Rise: 3 ft
- Run: 30 ft
Result: Grade = 10 %. Angle = 5.71 deg.
A shorter run with the same rise makes the slope noticeably steeper.
How to Interpret Your Results
| Range | Meaning | Action |
|---|---|---|
| < 3% | Very gentle slope | Often suitable for drainage or mild grading. |
| 3-8% | Moderate slope | Common in driveways, ramps, and exterior grading. |
| 8-15% | Steeper slope | Check traction, drainage, and local accessibility rules. |
| > 15% | Very steep slope | Review whether the design needs retaining, terracing, or a different layout. |
Frequently Asked Questions About Slope Angle Calculator
Sources
Last reviewed: March 2026