Plane Intercept Form (3D) Calculator

Published on: May 24, 2026

This Plane Intercept Form (3D) Calculator helps you write a plane in intercept form in three-dimensional space. Start with either a standard plane equation or the x-, y-, and z-intercepts, then rewrite the equation in the form x/a + y/b + z/c = 1. This makes it easier to see where the plane meets each axis. It is a simple way to check answers, understand the method clearly, and practise 3D coordinate geometry step by step.

Step-by-step method

  1. Put the plane into standard form Ax + By + Cz = d.
  2. Compute the intercepts a = d/A, b = d/B, c = d/C.
  3. Write intercept form x/a + y/b + z/c = 1.

Formula:

Ax + By + Cz = d
a = d/A, b = d/B, c = d/C
x/a + y/b + z/c = 1

Example 1: 2x+3y-4z=12

Step 1 - Put the plane into Ax + By + Cz = d and read off A, B, C, d.

In this problem: Rewrite your plane in standard form (if needed), then identify A, B, C and d.

A = 2, B = 3, C = -4
d = 12

Step 2 - Compute the intercepts.

In this problem: Use a = d/A, b = d/B, c = d/C.

a = d/A = 6
b = d/B = 4
c = d/C = -3

Step 3 - Write intercept form.

In this problem: Substitute a, b, c into x/a + y/b + z/c = 1.

x
6
+
y
4
+
z
-3
= 1
Intercept points: ( 6, 0, 0 ), ( 0, 4, 0 ), ( 0, 0, -3 )

Final answer: x/a + y/b + z/c = 1 with a=6, b=4, c=-3

Example 2: (2,3,-4)

Step 1 - Identify the intercepts a, b, c.

In this problem: Read the x-, y-, z-intercepts from the input.

a = 2, b = 3, c = -4

Step 2 - Write intercept form.

In this problem: Substitute a, b, c into x/a + y/b + z/c = 1.

x
2
+
y
3
+
z
-4
= 1

Step 3 - Optional: write standard form.

In this problem: Multiply through to remove denominators.

-12x + -8y + 6z = -24

Final answer: x/a + y/b + z/c = 1 with a=2, b=3, c=-4