Slope Calculator

Use the slope formula m = (y₂ − y₁) / (x₂ − x₁). Subtract the y-coordinates to get the rise, subtract the x-coordinates to get the run, then divide the rise by the run. Enter both points in the calculator above to get the slope instantly.

The slope formula is m = (y₂ − y₁) / (x₂ − x₁), often described as rise over run. It also equals tan(θ), where θ is the angle of inclination the line makes with the positive x-axis.

The angle of inclination is θ = arctan(m). For example, a slope of 1 corresponds to 45°, and a slope of 1.732 corresponds to 60°. This slope calculator shows the angle in degrees automatically for any two points you enter.

A horizontal line has a slope of 0 because the rise is 0. A vertical line has an undefined slope because the run is 0 and you cannot divide by zero. The calculator labels these cases and gives the matching line equation.

Percentage grade is the slope expressed as a percent: grade = slope × 100%. A slope of 0.05 is a 5% grade. Grades are commonly used for roads, ramps, roofs and trails to describe steepness.

Once you have the slope m, the slope-intercept equation is y = mx + b, where b is the y-intercept found with b = y₁ − m·x₁. The calculator builds the full equation y = mx + b for you and lists both intercepts.