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Slope Calculator

Calculate slope percentage, angle and gradient ratio.

Rise and run can use different units. The calculator converts them automatically.
Slope Result
SLOPE
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ANGLE
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GRADIENT
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RISE PER METRE
–
RISE PER FOOT
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Quick Slope Conversion
1 degree
1.75% slope
2 degrees
3.49% slope
5 degrees
8.75% slope
10 degrees
17.63% slope
45 degrees
100% slope
How the Slope Calculator Works

Slope percentage is calculated as rise divided by horizontal run, multiplied by 100.

Angle is calculated using the arctangent of rise divided by run. A gradient written as 1:n means one unit of vertical change for every n units of horizontal distance.

This calculator performs geometric slope conversions. Requirements for drainage, ramps, roads, roofs and other applications depend on the relevant design standard or code.

Slope Calculator

This slope calculator calculates the slope of a line from rise and run. It also provides the slope percentage, angle in degrees and gradient ratio for the entered values.

How to Calculate Slope

Slope describes the change in vertical elevation compared with the horizontal distance. It can be calculated by dividing the rise by the run.

Slope = Rise ÷ Run

A positive slope indicates an upward change, while a negative slope indicates a downward change. A zero slope represents a horizontal line.

Slope Percentage

Slope can also be expressed as a percentage. The slope percentage is calculated by multiplying the slope by 100.

Slope Percentage = (Rise ÷ Run) × 100

Slope Angle in Degrees

The slope angle represents the inclination of a line relative to the horizontal. It is calculated from the slope using the inverse tangent function.

Angle = arctan(Slope)

The calculator converts the resulting angle to degrees for easier interpretation.

Gradient Ratio

Slope can also be expressed as a gradient ratio in the form 1:n. The ratio indicates the horizontal distance corresponding to one unit of vertical rise or fall.

Frequently Asked Questions

What is slope?

Slope is the ratio of vertical change to horizontal change. It describes how steeply a line rises or falls.

How do I calculate slope from rise and run?

Divide the rise by the run. For example, a rise of 2 units over a run of 10 units gives a slope of 0.2.

How do I convert slope to percentage?

Multiply the slope by 100. A slope of 0.2 is therefore a 20% slope.

How do I convert slope to degrees?

Use the inverse tangent of the slope and express the resulting angle in degrees.

What is a 1:n gradient?

A 1:n gradient expresses one unit of vertical change for every n units of horizontal distance.

Note: Slope, percentage, angle and gradient ratio are different ways of expressing the same underlying inclination. Results depend on the entered rise and run values.