Slope Calculator
Find the equation of a straight line in every form, from two points, a point and slope, a slope and intercept, or ax + by + c = 0, with the angle, intercepts and distance from a point.
About the Slope Calculator
Slope measures steepness: how much y changes for each step in x. Positive slopes rise to the right, negative slopes fall, zero is flat and a vertical line has no defined slope.
The same line can be written several ways: slope-intercept y = mx + c, point-slope y − y₁ = m(x − x₁), the general form ax + by + c = 0, and the intercept form x/a + y/b = 1.
The formula
m = (y₂ − y₁) ÷ (x₂ − x₁), d = |ax₀ + by₀ + c| ÷ √(a² + b²)
- y = mx + c
- slope-intercept form
- y − y₁ = m(x − x₁)
- point-slope form
- ax + by + c = 0
- general form
- x/a + y/b = 1
- intercept form
Worked example
(1, 2) and (5, 10)
- m = 8 ÷ 4 = 2
- y − 2 = 2(x − 1), so y = 2x
- General form: 2x − y = 0
Questions people ask
What is a slope of 1?
A 45° line: y increases by 1 for each 1 in x.
How do I get the percent grade?
Multiply the slope by 100: a slope of 0.06 is a 6% grade.
Are parallel lines' slopes equal?
Yes. Perpendicular lines have slopes that multiply to −1.