How do you find the x-intercept?

Set y = 0 in the equation and solve for x. The x-intercept is the point (x, 0) where the line crosses the x-axis.

How do you find the y-intercept?

Set x = 0 and find y. In y = mx + b form, the y-intercept is simply b, the point (0, b).

Can a line have no x-intercept?

Yes. A horizontal line such as y = 3 never touches the x-axis, so it has no x-intercept. The line y = 0 is the x-axis itself.

Is the y-intercept the same as b?

Yes. In y = mx + b, the number b is the height where the line crosses the y-axis, which is the y-intercept.

Part 10 of 20 · LinesSee the whole course

How to find the x-intercept and y-intercept

By The Pip team · October 23, 2026 · 6 min read

Short answer

The y-intercept is where a line crosses the y-axis. Set x = 0 to find it. The x-intercept is where it crosses the x-axis. Set y = 0 and solve for x.

Two crossings, two zeros

Every point on the y-axis has x = 0. Every point on the x-axis has y = 0. That is the whole trick: to find where a line meets an axis, put 0 in for the letter that is 0 there, and solve for the other one.

The y-intercept: set x = 0

In y = mx + b, the y-intercept is just b, the point (0, b). For y = 2x − 4, it is (0, −4). If the equation is written another way, put x = 0 and see what y has to be. For 3x + 2y = 12:

x = 0: 3(0) + 2y = 12
2y = 12
y = 6, so the y-intercept is (0, 6)

The x-intercept: set y = 0 and solve

Put y = 0 and solve for x. For y = 2x − 4:

y = 0: 0 = 2x − 4
4 = 2x
x = 2, so the x-intercept is (2, 0)

This is “where the line hits the ground”, and it is also an equation to solve. That is why intercepts are the bridge into equations: see how to solve a linear equation. Try it below. Slide m and b and watch both intercepts move.

y = 2x − 4

Slope m 2

Starts at b −4

x = 0: y = −4
y = 0: 2x − 4 = 0, so x = 2

The line crosses the y-axis at (0, −4) and the x-axis at (2, 0).

Three examples

y = 2x − 4: y-intercept (0, −4), x-intercept (2, 0)
y = −3x + 6: y-intercept (0, 6), x-intercept (2, 0), because 0 = −3x + 6 gives x = 2
3x + 2y = 12: y-intercept (0, 6), x-intercept (4, 0), because 3x = 12 gives x = 4

Special cases

A horizontal line like y = 3 has a y-intercept of 3, but no x-intercept. It never touches the x-axis.
A vertical line like x = 2 has an x-intercept of 2, but no y-intercept.
A line through the origin, like y = 2x, has both intercepts at (0, 0).

Watch it explained in under a minute

The same idea, narrated step by step. Square version for sharing: download the 1:1 video.

The five mistakes to avoid

Setting the wrong letter to 0. For the y-intercept, set x to 0.
Giving b as the x-intercept. b is where the line meets the y-axis.
Sign slips: the x-intercept of y = 2x − 4 is +2, not −4.
Writing only one number when a point is asked for. Write (0, −4), not just −4.
Forgetting that a horizontal line (other than y = 0) has no x-intercept.

Try it yourself

Find both intercepts. Tap a question to see the answer.

1. y = 4x − 8

y-intercept: (0, −8). For the x-intercept, 0 = 4x − 8 gives x = 2: (2, 0).

2. y = −x + 5

y-intercept: (0, 5). For the x-intercept, 0 = −x + 5 gives x = 5: (5, 0).

3. y = 3

y-intercept: (0, 3). It is a flat line that never reaches the x-axis, so there is no x-intercept.

Where intercepts fit in

The y-intercept is the b of slope-intercept form, and the x-intercept is the solution of an equation. Next in this course: how to tell if a function is linear.