IP331.com | Online Tools
HomeTrigonometry ToolsGrade to Angle Calculator

Grade to Angle Calculator

Convert percent grade into slope angle

Grade to Angle Formula

angle = arctan(grade / 100)

Percent grade measures rise per 100 units of horizontal run. Dividing by 100 gives slope, and arctangent converts that slope into an angle.

Grade percent can be positive or negative. Positive values slope upward; negative values slope downward.

How Grade to Angle Conversion Works

A grade is a slope written as a percent. Because slope equals tangent of the angle, inverse tangent gives the angle in degrees.

Grade Percent

100×rise/run.

Slope

grade/100.

Angle

arctan converts slope to degrees.

Common Case

100% grade equals 45°.

💡 Example: A 10% grade gives angle=arctan(0.1)=5.710593°.

Applications of Grade to Angle

Road GradesRampsRoofsConstruction

Frequently Asked Questions

What is a grade to angle calculator?
It converts slope percent grade into an angle measured in degrees.
What is the grade to angle formula?
angle = arctan(grade/100).
How do I use this calculator?
Enter the grade percent and click Calculate.
What does 100 percent grade mean?
A 100% grade means rise equals run, which is a 45° angle.
Where is grade to angle used?
It is used for roads, ramps, roofs, trails, surveying, and construction.

More Trigonometry Tools

Free online calculators and tools covering mathematics, unit conversion, text processing, and daily life. Accurate, fast, mobile-friendly, and completely free to use.

© 2026 IP331.com — Free Online Tools. All rights reserved.

About · Contact · Privacy Policy · Cookie Policy · Terms of Use · Disclaimer · Sitemap