Mathematics (General)

Proportion Calculator

Lets users solve and check proportion instantly with formula, steps and examples — no manual math.

Enter your details

Your result
Missing value (x)
12

a/b = c/x → x = (b×c)/a = 12

About this calculator

Solves the proportion a/b = c/x for x by cross-multiplication: x = (b × c) / a. Enter three known values to find the fourth.

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