➗ Proportion Solver Calculator
Solve a/b = c/x for the missing value x.
Result
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How this calculator works
Solve a/b = c/x for the missing value x.
Formula
x=bc/a
Example
3/4 = 9/x gives x = 12.
Frequently asked questions
What does the Proportion Solver Calculator do?
Solve a/b = c/x for the missing value x.
Are the results exact?
The calculator follows the displayed formula. Rounded display values may differ slightly from full-precision results.
Can I use negative or decimal values?
Most fields accept decimals and negative values when they make sense for the formula.
How should I check an important result?
Review the formula, verify your entries, and confirm high-stakes work with a qualified teacher or professional.