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Y-Intercept Calculator.

Find the y-intercept from a slope and a point on the line.

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01

Set your values

Results update as you type.

intercept: 4

intercept

0.000000

Results update automatically as you type.

Use Cases

Graphing linear equations

Quickly determine where a line crosses the y-axis to plot it accurately on a graph.

Example: For a line with slope 2 passing through (3, 7), the y-intercept is 1.

Checking algebra homework

Verify your manual calculations when converting a point and slope into slope-intercept form.

Example: Slope = -1, point (4, 2) gives y-intercept = 6.

Frequently Asked Questions

How do I find the y-intercept using slope and a point?
Enter the slope (m) and the coordinates of a point (x, y) on the line. The calculator uses the equation y = mx + b, solving for b (the y-intercept) as b = y - mx.
What if the point is on the y-axis?
If the point's x-coordinate is 0, then the y-coordinate is the y-intercept itself. The calculator will still compute it correctly using the formula.
Can I use this calculator for vertical lines?
No, vertical lines have an undefined slope and cannot be represented in slope-intercept form. This calculator requires a defined slope value.

Tips & Common Mistakes

Tips

  • Ensure the slope is entered as a decimal or fraction (e.g., 0.5 or 1/2) for accurate results.
  • Double-check that the point coordinates are correct; a small error in x or y will change the y-intercept.
  • Use the result to write the full equation: y = mx + b, where b is the y-intercept you found.

Common Mistakes to Avoid

  • Entering the slope as the reciprocal or negative of the actual slope.
  • Mixing up the x and y coordinates when entering the point.
  • Forgetting that the y-intercept is the value of y when x = 0, not the value of x when y = 0.

Last updated: August 13, 2026