Direct Variation Calculator
Solve direct variation problems where y = kx. Find the constant of variation k, or solve for x or y given the relationship.
y varies directly as x: y = kx. Enter any two values to find the third.
Enter two values to solve.
Direct Variation Formula
y = kx (where k ≠ 0 is the constant of variation)
In direct variation, as x increases, y increases proportionally. The ratio y/x is always equal to k.
Example: y varies directly as x. If y = 12 when x = 4, find k and y when x = 7.
k = 12/4 = 3
y = 3 × 7 = 21
k = 12/4 = 3
y = 3 × 7 = 21
FAQ
What does the graph of direct variation look like?
A straight line through the origin (0, 0) with slope k. If k > 0, it goes up to the right. If k < 0, it goes down.
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Last updated: 2026-08-08