X and Y Intercepts Calculator

Choose slope-intercept form or standard form. The page returns where the line meets the axes. Horizontal lines have no x-intercept. Vertical lines have no y-intercept.

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How to find x and y intercepts

Pick slope-intercept or standard form so the matching coefficients appear.
For y = mx + b, enter slope m and intercept b. The default is m = 2 and b = -4.
For Ax + By = C, enter A, B, and C. Field b holds B when that form is selected.
Read the x-intercept and y-intercept rows. Horizontal and vertical cases say none instead of inventing a number.
Switch to the equation-of-a-line page when you start from two points rather than coefficients.

X and Y intercepts

Axis crossings of a plane line

X-intercept	Point where y = 0
Y-intercept	Point where x = 0
Slope form	x-intercept = -b / m when m ≠ 0
Standard form	Ax + By = C; set y = 0 or x = 0
Default slope example	y = 2x - 4 crosses at (2, 0) and (0, -4)
Degenerate case	A and B cannot both be zero in standard form

What x and y intercepts are

The x-intercept is where the graph meets the horizontal axis (y = 0). The y-intercept is where it meets the vertical axis (x = 0). For y = 2x - 4 the crossings are (2, 0) and (0, -4). Graphing these two points recovers the same line.

Intercepts from y = mx + b

The y-intercept is already the constant b. The x-intercept solves 0 = mx + b, so x = -b / m when m is not zero. A zero slope means a horizontal line that never meets the x-axis unless b is also zero (the x-axis itself).

Intercepts from Ax + By = C

Set y = 0 to get x = C / A when A is not zero. Set x = 0 to get y = C / B when B is not zero. If A = 0 the line is horizontal. If B = 0 the line is vertical. A and B cannot both be zero because that is not a line equation.

When intercepts matter

Sketch a quick graph from axis crossings, check algebra homework that asks for intercepts only, or convert between slope and standard form by reading both rows. Supply and demand break-even charts in economics use the same geometry with different labels.

Limits

Lines only. No parabolas, circles, or piecewise graphs. IEEE floating point applies. CZNull does not receive the numbers.

X and Y intercepts questions

What are the intercepts of y = 2x - 4?

The x-intercept is 2 and the y-intercept is -4, so the crossings are (2, 0) and (0, -4).

How do I enter standard form Ax + By = C?

Choose standard in the form list, then enter A, b (as B), and C. The page solves both axis crossings from those three coefficients.

Why does a horizontal line show no x-intercept?

A non-zero constant height never meets y = 0. The page reports none instead of dividing by a zero slope.

Why does a vertical line show no y-intercept?

A vertical line never meets x = 0 unless it is the y-axis. In standard form that is the B = 0 case.

Can A and B both be zero?

No. That input is not a line. The engine rejects A = B = 0 with a clear error.

Is the intercept the same as the intercept form of a line?

Intercept form x/a + y/b = 1 uses the two intercepts as parameters. This page starts from slope or standard coefficients and reports those intercepts.