Find the slope of the line through two points, with its angle and equation. Enter the coordinates.
Usage Tip
Positive slope rises left to right, negative falls. A slope of 1 is a perfect 45-degree diagonal.
The rise over the run
A vertical line has undefined slope; a horizontal line has slope zero.
The angle is measured from the horizontal.
Two points with the same x-value give a vertical line (undefined slope).
The slope of a line measures how steeply it rises or falls. It equals the change in y divided by the change in x between two points, often described as rise over run. A positive slope rises to the right, a negative slope falls, a slope of zero is horizontal, and a vertical line has an undefined slope because the change in x is zero.
The angle of the line follows from the arctangent of the slope. Slope appears in roof pitch, road grade, ramps, and any rate of change on a graph. A grade of 5 percent means a slope of 0.05, which is a rise of 5 units for every 100 units of run. The order of the two points does not matter as long as you subtract both coordinates in the same order.