AnyCalc

Finance & Math

Ratio Calculator

Simplify ratios and solve ratio proportions

Reviewed: AnyCalc Editorial|2026-07-19|Editorial policy|About

What this calculator does

A ratio calculator simplifies ratios and solves proportions for practical applications across cooking, mixing, finance, academics, and design. A ratio expresses the proportional relationship between two or more quantities — for example, a 3:2 ratio means for every 3 parts of one thing, there are 2 parts of another. The calculator can simplify ratios to their lowest terms (dividing both numbers by their GCD) and solve for missing values in proportions (if 3:5 = x:20, then x = 12). Proportional reasoning — the ability to work with ratios — is one of the most practical math skills. It is used in cooking, mixing solutions, financial analysis (price-to-earnings ratios, debt-to-income ratios), map reading, architecture, photography (aspect ratios like 16:9 and 4:3), and concrete mixing. Enter a ratio to simplify it, or set up a proportion with a missing value to solve it.

Ratio Calculator

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How to use

  1. 01
    Enter your ratio
    Input the ratio values or proportion you want to solve.
  2. 02
    Choose operation
    Select simplify or solve for an unknown proportion value.
  3. 03
    Get the answer
    View the simplified ratio, missing value, or scaled result instantly.

Ratio Calculator FAQ

How do I simplify a ratio?▾
Divide both parts of the ratio by their greatest common divisor (GCD). For example, to simplify 24:36, find GCD(24, 36) = 12, then divide both: 24/12 : 36/12 = 2:3. For ratios with three or more parts, divide all parts by the GCD of all the numbers.
How do I solve a proportion with a missing value?▾
Set up the proportion as a/b = c/d and cross-multiply: a × d = b × c. If 3:5 = x:20, then 3 × 20 = 5 × x, so 60 = 5x, and x = 12. This works for any proportion problem — identify which value is missing and solve the cross-multiplication equation.
How do I convert a ratio to a percentage?▾
Add the parts of the ratio to get the total, then divide each part by the total and multiply by 100. A ratio of 3:2 has a total of 5 parts. The first is 3/5 × 100 = 60% and the second is 2/5 × 100 = 40%. This is useful for understanding what proportion each component represents.
How do I scale a recipe using ratios?▾
Divide the desired servings by the original servings to get the scaling factor, then multiply every ingredient by that factor. To convert a 4-serving recipe to 6 servings: 6/4 = 1.5, so multiply all ingredients by 1.5. If the original calls for 2 cups of flour, use 3 cups.

Interpret carefully

Outputs are decision-support estimates, not a substitute for professional judgment.

  • Treating Ratio Calculator output as a final professional diagnosis, quote, or legal determination
  • Entering approximate values when the result is sensitive to units or precision
  • Applying the FAQ answer (“How do I simplify a ratio?”) to a special case without checking assumptions

Next steps

  1. Double-check inputs against your source documents (labs, statements, specs, or notes).
  2. Confirm the method below matches your use case before you act on the number.
  3. For medical, financial, or production decisions, verify with a qualified professional.

Disclaimer: Results are informational only and do not constitute medical, financial, legal, or professional advice. Report issues: sublimernj@gmail.com

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