Slope Calculator

What is the Slope Calculator?

Find the slope, y-intercept and equation of the line through two points. Slope measures how steep a line is — rise over run — and the calculator also gives the y-intercept and the full equation of the line.

How to use the Slope Calculator

1. Enter your x₁, your y₁, your x₂, your y₂.
2. Results update automatically as you type; you can also press Calculate.
3. Read the output: slope m, equation, angle.
4. Use the 📊 chart to see the result visually, then copy or share it.

Formula and method

Worked example

With x₁ = 1, y₁ = 3, x₂ = 5, y₂ = 11, the Slope Calculator returns slope m: 2; equation: y = 2x + 1; angle: 63.4349°.

Where the Slope Calculator helps in real life

An algebra student has the points (2, 5) and (6, 13). The calculator gives a slope of 2, an intercept of 1 and the equation y = 2x + 1.

A homeowner wants to know the grade of a driveway that rises 1.2 meters over 15 meters. The slope of 0.08, an 8% grade, helps judge whether it will be icy in winter.

Common mistakes to avoid

• Subtracting the coordinates in different orders for rise and run.
• Dividing run by rise instead of rise by run.
• Using two points with the same x-value, which gives an undefined slope.
• Losing a negative sign for downhill lines.

💡 Practical tip: A vertical line has an undefined slope, while a horizontal line has a slope of zero.

Tips for better results

• Keep the same point order for both subtractions.
• Multiply slope by 100 to express it as a percentage grade.
• Plot the points to confirm whether the line rises or falls.

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