Ratio Calculator

Simplify ratios and solve proportion problems of the form A:B = C:D.

Solve the proportion A : B = C : D — leave one box empty to solve for it.

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How to use Ratio Calculator

Three quick steps — no sign-up needed

  1. Step 1

    Enter known ratio terms

    Fill A, B, C, and/or D depending on which values you know in the proportion.

  2. Step 2

    Solve or simplify

    Calculate to simplify a ratio or find the missing term in A:B = C:D style problems.

  3. Step 3

    Read the result

    Use the simplified ratio or missing value in recipes, maps, and homework.

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About Ratio Calculator

Ratio Calculator simplifies ratios and solves proportions written like A:B = C:D. Students and cooks searching "ratio calculator", "simplify ratio", or "proportion calculator" need missing-term solves and reduced forms.

Enter the known terms among A, B, C, and D and calculate. Cross-multiplication finds a missing piece when three values are known; two-term inputs can be reduced by their GCD.

Keep units consistent (do not mix ml with cups mid-ratio without converting). For recipes, scale all ingredients by the same factor.

Arithmetic helper for ratios - check applied results in the real world when safety margins matter.

Benefits of Ratio Calculator

Simplify and solve Reduction and missing-term proportions in one tool.
A:B = C:D style Matches common homework layout.
Recipe and map friendly Scale quantities with less mental math.
Quick checks Verify hand cross-multiplication.

Frequently asked questions

How do I simplify a ratio?

Divide both parts by their greatest common divisor - the calculator does this when you enter two terms.

How do I find a missing proportion term?

Provide three of the four values in A:B = C:D and solve for the fourth.

Can ratios use decimals?

Yes, though fractions may be clearer for exact work.

Does order matter?

Yes - A:B is not the same as B:A.

Is this only for school?

No - recipes, dilutions, and scale models use the same math.