How to use the Ratio Calculator to simplify a ratio
Choose a calculation mode, enter the values beside its labels, and select Calculate. The result shows the formula, working, and assumptions for that mode. Whole numbers, decimals, and fractions are accepted where a number is required; Unit adds a label to the result.
- Select Simplify a ratio, Solve a missing term, or Divide a total by a ratio.
- Enter the values in Ratio terms, Ratio 1 and Ratio 2, or Total quantity and Ratio, depending on the selected mode.
- Enter an optional label in Unit. The label is carried into the result text.
- Select Calculate to see the result, formula, steps, and assumptions.
- Select Copy result or Download result (.txt) to save the displayed working, or select Reset to clear the fields.
How to simplify a ratio
Select Simplify a ratio and enter at least two terms in Ratio terms. Separate them with a colon, comma, or whitespace. Each term may be a whole number, decimal, or fraction such as 3/4. A slash between two numbers is read as a fraction, so 8/12 is rejected as a ratio.
Input: 8:12:20
Output: 2 : 3 : 5Terms must be zero or positive, with at least one nonzero term. For fractions, the calculator first clears the denominators, then divides every term by the greatest common divisor. The displayed ratio is in lowest terms.
How to solve a missing term in a ratio
Select Solve a missing term and fill Ratio 1 and Ratio 2 with the same number of terms. Mark exactly one term with ?. The calculator uses a fully known, nonzero matching pair to find the scale factor.
Ratio 1: 3:4
Ratio 2: ?:20
Output: 15 : 20Two unknowns, different term counts, or no fully known nonzero pair produces an error. Known terms may be zero when another matching position supplies the scale factor.
How to divide a total by a ratio
Select Divide a total by a ratio. Enter a zero or positive value in Total quantity and at least two zero-or-positive terms in Ratio. Each part uses total × term / (sum of all terms). The steps include a check that the parts add back to the total.
Total quantity: 120
Ratio: 2:3:5
Parts: 24 : 36 : 60The underlying fraction stays exact. A decimal may show repeating digits in parentheses or end with an ellipsis when it is truncated. Use the fraction in the result when you need the exact value.
Unit is optional display text, such as kg, ml, or people. It is carried into result text and does not convert values, so enter every value in the same unit. Parsing and calculation run in the browser, and the page code sends no request containing the values you enter.
Where ratio calculations come up
- Reduce
8:12:20to2:3:5before changing a recipe batch size. - Solve a missing value in two equivalent class or measurement ratios, then copy the completed ratio into notes.
- Divide a total among several portions, then use the returned parts in a worksheet or order.
When to use another math calculator
Use Fraction and Ratio Calculator for adding, subtracting, multiplying, or dividing fractions and mixed numbers. Use Proportion Calculator for a direct or inverse proportion such as a/b = c/d. For equations beyond these ratio forms, use Algebra Calculator. The Math Calculators category lists the other calculation types.
Frequently asked questions
How do I simplify a ratio?
Enter at least two terms in Ratio terms, select Simplify a ratio, and select Calculate. The calculator reduces all terms by their greatest common divisor.
Can the Ratio Calculator solve a missing term?
Select Solve a missing term, enter two same-length ratios, and mark exactly one value with ?. A fully known, nonzero matching pair must be available.
How do I split a total using a ratio?
Enter a zero or positive value in Total quantity and at least two terms in Ratio, then select Calculate. Each part follows that term's share of the ratio sum.
Does the Ratio Calculator convert units?
No. Unit is a label carried into the result text, so enter all values in the same unit.