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Proportion Calculator — Free Online Calculator

Solves proportions and finds the unknown value in a ratio.

What is it?

The proportion solver finds the missing value in a ratio equation of the form a : b = c : x (or any equivalent form with one unknown).

Formula

a / b = c / x → x = (b × c) / a Cross-multiply: a·x = b·c

Example

A recipe for 4 servings needs 300 g of flour. How much for 6 servings? x = (300 × 6) / 4 = 450 g.

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