Direct Variation Calculator

The Direct Variation Calculator finds the constant of variation k from a known pair (x, y) using y = kx, then predicts y for a new x. Enter a known x and y and the new x.

Formula

y = kx, so k = y ÷ x
  • In direct variation, y changes in constant proportion to x.
  • Once k is known, any y can be predicted from its x.

x=4, y=12, new x=7

Inputs
  • Known x: 4
  • Known y: 12
  • New x: 7

k = 12/4 = 3, so y = 3x and at x = 7, y = 21.

Frequently asked questions

What is direct variation?
A relationship y = kx where y is always a constant multiple k of x, passing through the origin.