Math

Free Ratio Calculator

Solve A:B = C:D for the missing term.

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Inputs

Result

D

12.0000

Simplified3:4 = 9:12.0000

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Short answer

Solve A:B = C:D for the missing term.

What is the Ratio Calculator?

Solve A:B = C:D for the missing term.

How does the Ratio Calculator work?

Enter the inputs above and read the result.

Formula

D = B · C / A

Variables

    Explanation

    Cross-multiplication of two equal ratios.

    Examples

    Applications

      Advantages

        Limitations

          Common mistakes

            Tips

              Related concepts

              The Ratio Calculator sits inside the Math Calculators hub, in the algebra & equations cluster. Solving for unknowns and manipulating expressions. Understanding the terms below makes the output easier to interpret and easier to compare against neighbouring measures.

              equationrootexponentlogarithmsequenceproportion

              Practical use cases and industry applications

              Understanding Ratio

              Solve A:B = C:D for the missing term. Within math calculators, ratio belongs to the algebra & equations cluster, where it shares terminology and assumptions with closely related tools.

              Learning how ratio is calculated

              Cross-multiplication of two equal ratios. Working through the variables one at a time — — makes the result reproducible by hand and easier to sanity-check.

              Using ratio to make a decision

              Because outputs depend on the assumptions you enter, run more than one scenario before committing to a figure.

              How ratio compares with related measures

              equation, root, exponent, logarithm all describe adjacent aspects of algebra & equations. Comparing this calculator's output against those measures — using the related tools listed on this page — prevents a single metric from being read in isolation.

              Frequently asked questions

              Related calculators

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