Ratio Calculator
Simplify a ratio or solve for a missing number to keep two ratios equal. Enter your values and get the answer instantly.
How it works
- 1
Enter the ratio
Two numbers, such as 4 and 6.
- 2
See it simplified
Reduced to lowest terms using the greatest common divisor.
- 3
Solve for a missing value
Add a third number to find the matching fourth value.
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Frequently asked questions
Divide both numbers by their greatest common divisor.
Simplifying and scaling ratios
A ratio like 4:6 simplifies to 2:3 by dividing both sides by their greatest common divisor. Scaling a ratio (finding an equivalent one, like 2:3 = 8:12) uses cross-multiplication: if a:b = c:d, then d = b × c ÷ a.
Ratios are used for recipes, maps and scale models, mixing solutions, and comparing quantities like students per teacher.