Slope & Intercept Calculator

How it is calculated

From two points the tool finds the slope m = (y₂ − y₁) / (x₂ − x₁) and then the intercept b = y₁ − m × x₁, which gives the line y = m·x + b. Slope is the change in y per one unit of x, and the intercept is the value of y where the line crosses the y axis (x = 0). Both are shown with 4 decimals. If the two x values are equal the line is vertical, its slope is undefined, and the tool returns no result. Any units work as long as both points use the same ones.

Common mistakes

• Subtracting in a different order on top and bottom, for example y₂ − y₁ over x₁ − x₂. That flips the sign of the slope.
• Entering the same x for both points. A vertical line cannot be written as y = mx + b, so there is no result.
• Swapping x and y when the data is a table with the dependent variable in the first column.
• Reading the intercept as the value at the first point. It is the value at x = 0, which can be far from the points you entered.