Find the slope between two points, convert rise and run to slope, or calculate slope from an angle with the Slope Calculator. Results update instantly as you type.
Slope calculator
Using the slope calculator
The calculator offers three modes for calculating slope:
Two Points: Enter coordinates for two points (x₁, y₁) and (x₂, y₂). The calculator finds slope using the classic rise-over-run formula, plus gives you the line equation in y = mx + b form and the distance between points.
Rise & Run: Already know the vertical change (rise) and horizontal change (run)? Enter them directly. Useful when you've already measured or calculated the differences.
Angle: Enter an angle in degrees or radians and get the equivalent slope. The calculator uses the tangent function to convert angle to slope.
All modes show the slope as a decimal, fraction (simplified), angle, and percentage grade. The two-points mode also displays the complete line equation.
What is slope?
Slope measures the steepness of a line - how much y changes for every unit change in x. A positive slope means the line rises from left to right; a negative slope means it falls.
m = \frac{y_2 - y_1}{x_2 - x_1} = \frac{\text{rise}}{\text{run}}Some special cases:
- Slope = 0: Horizontal line (no rise)
- Slope = 1: Line rises at 45° (rise equals run)
- Slope = undefined: Vertical line (run = 0, division by zero)
Slope as angle vs. percentage
You'll often see slope expressed as an angle or percentage grade, especially in construction and road design:
\text{Angle} = \arctan(m)\text{Percentage grade} = m \times 100\%A 100% grade means the rise equals the run (45° angle). A typical highway might have a 6% grade maximum, while a steep driveway could be 15-20%.
Slope example
Find the slope between points (2, 3) and (8, 15):
m = \frac{15 - 3}{8 - 2} = \frac{12}{6} = 2The slope is 2, meaning y increases by 2 for every 1 unit increase in x. This corresponds to an angle of about 63.43° or a 200% grade.
Related slope tools
- Slope Intercept Form Calculator - Find y = mx + b from points or slope
- Find Missing Coordinate Calculator - Solve for x or y given slope
- Percentage Slope to Degrees Calculator
- Degrees to Percentage Slope Calculator
