In coordinate geometry, the slope (often represented by the letter m) measures the steepness and direction of a straight line. Slope is commonly described as "rise over run," which compares how much a line moves vertically (along the Y-axis) for a set distance horizontally (along the X-axis). Calculating slope is a core mathematical concept in graphing, drafting, engineering, and economics.
To find the slope between two points (x1, y1) and (x2, y2), you subtract the starting Y-value from the ending Y-value (rise) and divide by the ending X-value minus the starting X-value (run). The slope formula is: m = (y2 - y1) / (x2 - x1).
If you also want to find the straight-line distance between the two coordinate points, you can use our measuring straight-line distances tool. For curves instead of straight lines, you would use our curved quadratic equations tool. To see the angles, you can check our solving triangle properties tool.
The sign and magnitude of the slope value tell you how the line behaves on a graph. A positive slope means the line rises from left to right. A negative slope means the line falls from left to right.
A slope of exactly zero indicates a perfectly horizontal line (no rise). A vertical line has an undefined slope because the horizontal run is zero, and you cannot divide a number by zero.
Suppose a surveyor plots two points on a map: Point A at coordinates (2, 3) and Point B at coordinates (6, 11).
To find the slope, we calculate the rise: 11 - 3 = 8. Next, we calculate the run: 6 - 2 = 4. Dividing the rise by the run: 8 / 4 = 2. The slope of the line is exactly 2. This means that for every unit the line moves to the right, it rises by 2 units vertically. The slope-intercept equation of this line is written as y = 2x - 1. This example shows how coordinate points define linear boundaries.