Slope Percentage Calculator
Convert a rise and run into slope as a percentage, ratio and angle.
Grade or slope as a percentage is widely used for roads, ramps and roofs.
How the Math Works
The Slope Percentage Calculator uses the fundamental formula slope% = (rise ÷ run) × 100 to convert vertical elevation into a percentage representation. This calculation measures the steepness of an incline by comparing the vertical distance (rise) to the horizontal distance (run). The result expresses how many units of vertical change occur per 100 units of horizontal distance, making it easy to understand gradients in practical terms.
Practical Applications
To use this calculator, simply enter the vertical rise and horizontal run measurements from your project or survey. For construction projects, measure the height difference between two points and the horizontal distance between them. In landscaping, determine the elevation change across a slope and the ground distance. The calculator instantly provides the slope as a percentage, a ratio form, and the angle in degrees, allowing you to assess suitability for drainage, accessibility, or design requirements.
Day-to-Day Use
This calculator helps with everyday tasks like determining if a driveway is too steep for safe driving, checking if a wheelchair ramp meets accessibility standards, or assessing whether your garden soil will drain properly. It's useful for DIY projects, real estate evaluations, hiking trail planning, and ensuring proper water flow in home drainage systems. Understanding slope percentages helps you make informed decisions about accessibility, safety, and functionality in both residential and outdoor environments.
Worked example
Rise 3 over run 20 → 3 ÷ 20 × 100 = 15% (about 8.5°).
FAQ
Is 100% slope vertical?
No — it is 45°. A vertical slope is undefined (infinite percentage).