Grade Slope Calculator
Vertical Rise (in feet or meters): Horizontal Run (in feet or meters): Calculate Grade Slope: In construction, civil engineering, landscaping, and roadway design, grade slope is a fundamental concept. It indicates how steep or gentle a surface is, and is expressed as a percentage—known as the grade or slope grade. The Grade Slope Calculator makes…
In construction, civil engineering, landscaping, and roadway design, grade slope is a fundamental concept. It indicates how steep or gentle a surface is, and is expressed as a percentage—known as the grade or slope grade.
The Grade Slope Calculator makes it easy to determine this percentage. Whether you’re designing a driveway, grading land, or checking road compliance, you can instantly calculate the grade from two measurements: rise (vertical height) and run (horizontal distance).
Formula
To calculate grade slope (%), use the formula:
Grade Slope % = (Rise ÷ Run) × 100
Where:
- Rise is the vertical distance
- Run is the horizontal distance
- The result is a percentage that represents the incline/decline of the surface
For example, a rise of 5 feet over a run of 100 feet gives:
(5 ÷ 100) × 100 = 5% grade
How to Use the Grade Slope Calculator
- Measure the vertical rise (in feet, meters, or any unit)
- Measure the horizontal run (same unit as rise)
- Enter both values in the calculator
- Click “Calculate”
- You’ll get the slope percentage instantly
Make sure both values are in the same unit (feet, meters, inches, etc.) to get accurate results.
Example
Suppose:
- Rise = 4 feet
- Run = 80 feet
Grade Slope % = (4 ÷ 80) × 100 = 5%
That means the slope rises 5 feet for every 100 feet traveled horizontally.
Grade Slope Classification
| Grade % | Description | Use Case |
|---|---|---|
| 0% | Flat/level surface | Indoor floors, walkways |
| 1%–3% | Gentle slope | Drainage, sidewalks |
| 4%–8% | Moderate slope | ADA-compliant ramps |
| 8%–15% | Steep slope | Driveways, parking lots |
| 15%+ | Very steep/dangerous | Roads, mountain trails |
FAQs About Grade Slope Calculator
1. What is a grade slope?
It’s the incline of a surface, expressed as a percentage of vertical rise over horizontal run.
2. What does a 0% grade mean?
It means the surface is completely flat—no elevation change.
3. What is a 100% grade?
That’s a 45-degree slope. Rise equals run.
4. Can slope be negative?
Yes. A negative grade indicates a decline rather than an incline.
5. What is a good slope for driveways?
Typically 2% to 15%, depending on the type of vehicle and climate (for snow or rain drainage).