Direct Variation Calculator

Find the constant k in y = kx and predict a new y.

Constant k 3

New y 21

Formula: k = y ÷ x ; y₂ = k · x₂

Step-by-step with your numbers:

1. Values used:

2. Known x = 4

3. Known y = 12

4. New x = 7

6. Constant k = Known y / Known x = 12 / 4 = 3

7. New y = 21

Did we solve your problem today?

Direct variation describes two quantities that grow in proportion: y = kx.

The math behind it

The constant of variation is k = y ÷ x. Once you know k, any new y is k times the new x.

y = 12 when x = 4 → k = 3, so at x = 7, y = 21.

How is this different from inverse variation?

Direct variation is y = kx (both rise together); inverse variation is y = k/x (one rises as the other falls).