Slope Calculator
Find slope, rise, run, angle of incline, distance, percent grade, and the line equation from two points — with an interactive graph.
How to Use
Enter the x and y coordinates of two points above. Results update automatically as you type — no need to click Calculate, though you can. The graph redraws live to show the line and its rise/run triangle.
Related Calculators
Slope Formula & Line Equation
The slope m between two points is m = (y2 − y1) / (x2 − x1) = rise / run. With the slope known, the full line equation follows: y = mx + b, where b = y1 − mx1 is the y-intercept.
From the same slope you can derive: angle = arctan(m) (in degrees), distance = √(run² + rise²), and grade = m × 100%. A negative slope means the line falls left-to-right.
Slope, Angle & Grade Conversion Reference
1% grade: 0.57° · 5% grade: 2.86° · 10% grade: 5.71°
25% grade (m=0.25): 14.04° · 50% grade (m=0.5): 26.57°
100% grade (m=1): 45° · 173% grade: 60°
ADA max ramp grade: 8.33% (4.76°) · Steep residential roof: 33–50% (18–27°)
Grade above 100% means an angle steeper than 45°. An infinite grade (vertical) is undefined — use the angle (90°) instead.
Understanding Slope: Rise Over Run
Slope measures how steep a line is — the ratio of vertical change (rise) to horizontal change (run). It is one of the most fundamental concepts in algebra, geometry, and any field that deals with rates of change. The standard formula m = (y2 − y1)/(x2 − x1) gives you a single number that completely describes a line's direction and steepness.
For example, the points (1, 2) and (4, 8) have a rise of 6 and a run of 3, giving a slope of m = 2. The line equation is y = 2x, it runs at an angle of about 63.43°, the distance between the points is √45 ≈ 6.71 units, and the grade is 200%. Enter those coordinates in CalcSolver to see the graph and confirm every value.
In the real world, slope governs roof pitch (rise per 12 inches of run), road gradients (the % on highway warning signs), wheelchair ramps (ADA caps this at 8.33%), and statistical trend lines (linear regression's "m"). Use CalcSolver's triangle calculator for area/perimeter work and the equation solver for solving related algebra problems.
Sponsored Content
The following content is provided by our advertising partner and does not affect the calculator experience.
Frequently Asked Questions
How do you calculate slope from two points?
Slope (m) equals rise over run: m = (y2 − y1) / (x2 − x1). Subtract the y-coordinates to get the rise, subtract the x-coordinates to get the run, then divide. A positive slope rises left-to-right; a negative slope falls. A vertical line has an undefined slope (run = 0).
What is the difference between slope, grade, and angle of incline?
Slope (m) is the raw ratio rise/run. Grade is slope expressed as a percentage (grade = m × 100%). Angle of incline is the arctangent of the slope in degrees (θ = arctan(m)). A 100% grade equals a 45° angle. Road signs use grade; geometry problems usually want slope or angle.
What does a slope of 0 mean?
A slope of 0 means the line is perfectly horizontal — there is no rise no matter how far you run (y2 − y1 = 0). A vertical line has an undefined slope because run = 0 makes the division impossible (x2 − x1 = 0).
How is slope used in real life?
Slope appears everywhere: roof pitch (rise over 12-inch run), road grade signs (%), wheelchair ramp design (ADA requires ≤4.8° incline, about 8.3% grade), drainage planning, skiing difficulty ratings, and linear regression trend lines in statistics.