Math

Slope Calculator

Calculate slope percent, angle, and line length.

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Inputs

Adjust the assumptions to match your scenario. Results update instantly.

Results

Primary outputs and comparison insights are built from the current inputs.

Slope ratio

0.33

Rise divided by run as a simple numeric slope ratio.

Slope percent

33.33%

Slope shown as a percentage grade.

Angle degrees

18.43

Angle of the line above the horizontal in degrees.

Line length

12.65

Straight-line distance between the two points.

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How this Slope Calculator works

The Slope Calculator converts rise and run into a slope ratio, grade percentage, angle, and line length for geometry, drafting, and practical layout work. Enter rise and run to estimate slope ratio, slope percent, and angle degrees. The calculator updates instantly and adds a comparison table plus chart so you can test the sensitivity of the result before you use it in a decision.

Quick guide

Jump to the section you need, then return to the slope calculator.

Inputs

  • Vertical change between two points.
  • Horizontal change between two points.

Outputs

  • Rise divided by run as a simple numeric slope ratio.
  • Slope shown as a percentage grade.
  • Angle of the line above the horizontal in degrees.
  • Straight-line distance between the two points.

Assumptions

  • Rise and run are measured in the same unit system.
  • The line is straight between the two points.

Tips

  • Use grade percent when comparing ramps or roads and angle when comparing geometry layouts.
  • A very small run can make percent grade explode, so double-check that input first.

Slope Calculator formula guide

Use these slope calculator formulas to audit the output or explain it to someone else.

2 formulas

Slope Ratio = Rise ÷ Run
Angle = arctangent(Rise ÷ Run)

Slope Calculator examples

Review a ready-made slope calculator scenario, copy it, then tweak inputs to match your case.

Example

2 inputs4 outputs

Ramp layout check

Inputs

  • Example input Rise: 1.2
  • Example input Run: 12

Outputs

  • Example result Slope ratio: 0.1
  • Example result Slope percent: 10%
  • Example result Angle degrees: 5.71
  • Example result Line length: 12.06

Slope is easy to calculate, but choosing the right representation—ratio, percent, or degrees—makes the result much more useful in practice.

Slope by rise

5 of 5 rows
RiseSlope percentAngle degrees
216.67%9.46
325%14.04
433.33%18.43
541.67%22.62
650%26.57

Slope percent and angle can move quickly when run is short, so keep the same run value when comparing scenarios.

Grade change by rise

Highest: 6 (50%)Lowest: 2 (16.67%)
RiseSlope percent

Focus point

2

16.67%

Position

#1 of 5

Original order

Share of total

10%

Total: 166.67%

PositiveNegative

Slope percent and angle can move quickly when run is short, so keep the same run value when comparing scenarios.

References

  • Slope, grade, and angle formulas
  • Right-triangle relations for layout geometry

Learn more

Guides connected to the slope calculator

Use these short guides when you want the decision framework behind the numbers, not just the raw output.

Category guide

Math Calculator Guide

Pick the right math calculator by problem type: arithmetic, ratios, coordinates, geometry, or measurement.

FAQ

Slope Calculator FAQ

What does the Slope Calculator do?

The Slope Calculator converts rise and run into a slope ratio, grade percentage, angle, and line length for geometry, drafting, and practical layout work. Enter rise and run to estimate slope ratio, slope percent, and angle degrees. The calculator updates instantly and adds a comparison table plus chart so you can test the sensitivity of the result before you use it in a decision. It is part of our math toolkit.

What inputs do I need?

Typical inputs include Vertical change between two points., Horizontal change between two points..

How are the results calculated?

We follow the formulas and assumptions outlined in the "How this calculator works" section. You will see outputs like Rise divided by run as a simple numeric slope ratio., Slope shown as a percentage grade., Angle of the line above the horizontal in degrees..

Can I share or download the results?

Use the Copy link or Print buttons to share your results. If a table or chart appears, you can download the data as CSV.

Is my data stored?

No. Calculations run in your browser and we do not store your inputs.

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