About the Slope and Grade Calculator Online Free Tool

The Slope and Grade Calculator Online Free Tool converts rise and horizontal run into rise/run ratio, percent grade, angle, and 1-in-N notation. It is helpful for ramps, drainage, roads, landscape grading, and quick civil layout checks.

How to Use the Slope and Grade Calculator Online

1. Enter the required inputs in the fields above using the units shown on the labels.
2. Select any mode, shape, or method options so the calculation matches your scenario.
3. Run the calculation and review the result summary in the output panel.
4. Check the units, assumptions, and project requirements before using the result outside preliminary review.

Choosing Options Correctly

Use the vertical rise and horizontal run in the same unit system. The run should be plan distance, not slope distance.

Common Use Cases

• Convert field rise and run measurements into a percent grade.
• Compare a proposed slope against accessibility, drainage, or project limits.
• Translate between angle, ratio, and grade language for reports or sketches.

Quick FAQ

What is the difference between slope ratio and grade percent?
Grade percent is rise divided by run times 100. A slope ratio expresses the same relationship as rise:run or run:rise.

Should rise and run use the same unit?
Yes. Use the same unit for both so the ratio and grade are meaningful.

Can this calculate drainage design?
No. It converts slope values; drainage design still needs flow, roughness, surface, and code checks.

What if run is zero?
A zero run is vertical and cannot be represented as a normal percent grade. Check the input before using the result.