Math

Slope Percentage Calculator

Convert a rise and run into slope as a percentage, ratio and angle.

Calculated Output

Slope (%) 15

Angle (°) 8.531

Formula: slope% = rise ÷ run × 100

Step-by-Step Breakdown

1. Values used:

2. Rise (vertical) = 3

3. Run (horizontal) = 20

5. Slope = 15%

6. Angle = 8.531°

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The math behind it

A slope percentage is rise ÷ run × 100. A 100% slope is a 45° angle (rise equals run).

Rise 3 over run 20 → 3 ÷ 20 × 100 = 15% (about 8.5°).

Is 100% slope vertical?

No — it is 45°. A vertical slope is undefined (infinite percentage).