Ratio Calculator
Work with ratios — simplify them, scale them, and solve for a missing value.
Comparing quantities
A ratio compares quantities, like two parts of one thing to three of another. This simplifies ratios, scales them up or down, and solves for a missing term, so you can work with the proportions that come up in recipes, mixing, maps and design.
Enter your ratio to simplify, scale or solve it.
Ratios and proportion in practice
The everyday power of ratios is proportion — keeping the same relationship while changing the amounts. Scaling a recipe up for more people, mixing a solution to the right strength, reading a map's scale, or resizing an image without distortion are all ratio problems, where you know the ratio and one quantity and need the other. Simplifying a ratio to its lowest terms, the same idea as simplifying a fraction, makes it easier to grasp. Solving for a missing term is the classic proportion problem: if this much of one gives that much of another, how much do you need for a different amount. It is one of the most broadly useful bits of practical maths.
Ratio Calculator FAQ
What can I do with a ratio here?
Simplify it to lowest terms, scale it up or down, and solve for a missing value in a proportion.
Where are ratios used day to day?
Scaling recipes, mixing solutions, reading map scales, and resizing without distortion — anywhere a proportion must stay the same as amounts change.
Is anything uploaded?
No. The calculation happens in your browser.