Inverse Variation Calculator

This calculator works out the constant of inverse variation between two quantities and uses it to predict a new value, without you needing to rearrange the formula by hand. Inverse variation describes pairs of numbers that move in opposite directions in a fixed proportion, following the rule y equals k divided by x, so as x doubles, y halves, and their product always equals the same constant k. Everyday examples include speed and travel time over a fixed distance, workers on a job and how long it takes to finish, or pressure and volume of a gas at constant temperature. To use it, enter a known x value and its matching y value, then enter the new x you want to solve for. The calculator multiplies your known pair to find the constant k, shows the relationship as y equals k divided by x, and returns the constant k alongside the predicted y at your new x. It is useful for checking homework, working through science and maths problems, or quickly confirming a proportional relationship without doing the algebra yourself. Keep in mind the calculator assumes a true inverse relationship holds between your two quantities and that you have entered valid, non-zero numbers, since dividing by an x of zero produces an undefined result. The formula, a worked example and the underlying assumptions are set out below.

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