Convert a rise and run into percent grade and the slope angle. Rise may be negative for a fall.
| Grade (%) | – |
| Angle (°) | – |
Use this calculator for a road, a drain, or a site grade. Enter the vertical rise (negative for a fall) and the horizontal run.
Percent = (rise ÷ run) × 100. Angle = arctan(rise ÷ run) in degrees. Rise and run can be entered in metres (m) or feet (ft); only the ratio matters, so any consistent pair works.
This is a right-triangle conversion. It does not set a drainage code or a road design speed.
Rise: Vertical change, in m or ft. Negative values are a fall.
Run: Horizontal distance, in m or ft. Must be positive.
Grade (%): Slope as a percent.
Angle: Slope angle in degrees from the horizontal.
Related calculators