Slope & Gradient Calculator
Pick what you know (rise and run, a percentage, an angle or a ratio) and the calculator gives the rest.
Your result will appear here after you press Calculate.
How this calculator works
Slope % = rise ÷ run × 100
Angle = arctan(rise ÷ run)
Ratio = 1 : (run ÷ rise)
Slope length = √(rise² + run²)
Assumptions and limits
- Slope is measured as vertical rise over horizontal run. Angles must be below 90°.
This tool gives an approximate estimate from the values you enter. It is not a substitute for professional engineering design, site inspection, official quotations or applicable building regulations. See the calculator disclaimer.