Ratio Calculator
Simplify ratios or solve a missing value in a proportion.
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Quick example
How ratios and proportions are used
Ratios compare the relationship between two or more quantities. They are useful for recipes, scaling, sharing, design sizes, and unit relationships. This calculator can simplify ratios or solve a missing value in a proportion.
Before calculating, check that the units match and that the ratio direction is correct. A ratio of 2:3 is different from 3:2.
Formula or logic
- Proportion: a ÷ b = c ÷ d
- A missing value can be solved by cross multiplication
Example
If a recipe ratio is sugar:water = 2:5 and water is 500 ml, sugar should be 200 ml to keep the same ratio. Reversing the ratio gives a different result.
Common questions
Does a ratio need to use whole numbers?
Not always, but simplified whole-number ratios are usually easier to read and compare.
Can ratios be used for scaling dimensions?
Yes. If width and height keep the same ratio, the shape can be enlarged or reduced without distortion.
How is a ratio different from a percentage?
A ratio compares quantities with each other. A percentage usually expresses a value as a share out of 100.