Tool Factory

Slope Calculator

Find the slope between two points, plus rise, run, angle, y-intercept, and the line equation. Everything runs in the browser.

  • Two points → slope
  • Rise / run & angle
  • Vertical & horizontal
  • Stays on your device

Slope is rise over run: m = (y₂ − y₁) / (x₂ − x₁). A vertical line (same x) has undefined slope.

Working

m = (6 − 2) / (3 − 1) = 4 / 2 = 2

Numbers stay on this device. Nothing is uploaded, and there is no account.

Slope is rise over run. Given points (x₁, y₁) and (x₂, y₂), compute m = (y₂ − y₁) / (x₂ − x₁). The same formula gives the angle of the line via arctan(m) and the y-intercept from rearranging into y = mx + b.

Example: from (1, 2) to (3, 6), rise = 4 and run = 2, so m = 2. The angle is arctan(2) ≈ 63.43°, the y-intercept is 0, and point-slope form is y − 2 = 2(x − 1). A vertical line such as x = 4 has undefined slope; a horizontal line such as y = 5 has slope 0.

Break a number into primes with the factoring calculator, find the greatest common factor with the GCF calculator, simplify a ratio with the ratio calculator, or solve A / B = C / D with the proportion calculator. Browse more tools in the Math hub.

How to use the slope calculator

  1. Enter the coordinates of the first point (x₁, y₁).
  2. Enter the coordinates of the second point (x₂, y₂).
  3. Read the slope, rise, run, angle, y-intercept, and equation.
  4. If the points share an x-value, the result shows an undefined (vertical) slope.

Frequently asked questions

What is slope?

Slope measures how steep a line is. Between two points (x1, y1) and (x2, y2), the slope m is the change in y divided by the change in x: m = (y2 − y1) / (x2 − x1). A larger absolute value means a steeper line.

How do I find the slope from two points?

Subtract the y-coordinates to get the rise, subtract the x-coordinates to get the run, then divide: m = rise / run. For (1, 2) and (3, 6), rise = 4 and run = 2, so m = 2.

What does a negative slope mean?

A negative slope means the line goes down as you move from left to right. For example, (0, 4) and (2, 0) give m = −2. A positive slope goes up from left to right.

What is the slope of a horizontal or vertical line?

A horizontal line has slope 0 because the rise is 0. A vertical line has undefined slope because the run is 0 and you cannot divide by zero. This calculator labels vertical lines clearly instead of returning a number.

How is slope related to the angle of a line?

The angle θ that a non-vertical line makes with the positive x-axis satisfies tan(θ) = m, so θ = arctan(m). This calculator shows that angle in degrees. A slope of 1 is 45°, and a slope of 0 is 0°.

What is point-slope form?

Point-slope form writes the line through a known point (x1, y1) with slope m as y − y1 = m(x − x1). From there you can expand to slope-intercept form y = mx + b, where b is the y-intercept.

Can I use decimals in the slope calculator?

Yes. Enter any finite decimals for the four coordinates. The calculator validates that each value is a real number and rejects empty or non-numeric input.

Is my information saved or uploaded?

No. The slope calculator runs entirely in your browser. Numbers are not sent to a server or stored, and there is no account.

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