Slope Calculator
Slope of a line from two points.
How it works
Slope m = (y₂ − y₁) ÷ (x₂ − x₁)
Slope is the steepness of a line: positive rises, negative falls, 0 is horizontal. When x₁ = x₂ the line is vertical and the slope is undefined.
FAQ
What is the slope of a vertical line?
A vertical line has an undefined slope (division by zero); it is shown as "—".
Worked example
Through (1, 2) and (4, 11): m = (11−2) ÷ (4−1) = 3.
Point-slope: y − 2 = 3(x − 1), i.e. y = 3x − 1.
Notes and limitations
A zero denominator means a vertical line with undefined slope (not zero); horizontal lines have slope 0. Equal slopes mean parallel; a product of −1 means perpendicular.