∝ Proportion Calculator
How It Works
Solve proportion problems and find missing values in proportional relationships. Use Proportion Calculator to apply the displayed mathematical method to your values and see the result immediately.
The result is most useful when the inputs match the definitions used by this calculator. For this tool, the underlying method is: If A : B = C : D, then D = (B × C) / A. Compare the output with the worked example, then change one meaningful input at a time to see how the result responds.
Understanding Proportion
Proportion describes a mathematical relationship between the values entered in the calculator. Understanding the reference values and formula helps you interpret the result correctly. Check units, signs, reference values, and rounding conventions when using the result for an important calculation. Review the proportion inputs and units before relying on the result.
When to Use This Calculator
Use Proportion Calculator to apply the displayed mathematical method to your values and see the result immediately.
Practical tip: For this Proportion Calculator, identify the reference values and units first, then change one meaningful input at a time so the effect on the result is clear.
Formula
If A : B = C : D, then D = (B × C) / A
Example
If 2:5 = 8:x, then x = (5 × 8) / 2 = 20. Try changing one input to see how the result responds.