Slope Calculator

Slope between two points

The slope of a line tells you how steep it is — how much y changes for each step in x. From two points this calculator finds the slope, the full line equation, the distance between the points, and their midpoint.

The formulas

• Slope m = (y₂ − y₁) ÷ (x₂ − x₁)
• Line equation y = mx + b, where b is the y-intercept
• Distance = √((x₂ − x₁)² + (y₂ − y₁)²)
• Midpoint = ((x₁ + x₂) ÷ 2, (y₁ + y₂) ÷ 2)

FAQ

Why is my slope "undefined"?

When both points share the same x-value, the line is vertical and its slope is undefined (you'd be dividing by zero). The calculator reports the line as x = a constant instead.

What does a slope of zero mean?

A slope of zero means the line is perfectly horizontal — y doesn't change as x increases. This happens when both points share the same y-value, and the line equation reduces to y = a constant.

What does a negative slope tell me?

A negative slope means the line goes downhill from left to right: as x increases, y decreases. The steeper the downhill, the larger the slope's absolute value, while a positive slope rises from left to right.

How is the y-intercept found from two points?

Once the slope m is known, the y-intercept b comes from rearranging y = mx + b to b = y − mx using either point's coordinates. That gives the full line equation, which the calculator displays in slope-intercept form.

Is this calculator free and private?

Yes — it's free with no sign-up, works on mobile, and computes everything in your browser, so the coordinates you enter are never sent anywhere.