Ratio Calculator
Simplify a ratio to lowest terms, or solve a proportion A:B = C:? for the missing value — instantly, in your browser.
Simplify a ratio to its lowest terms, or solve a proportion for the missing number. It runs in your browser.
How to use it
- Choose simplify or proportion.
- To simplify, enter the two parts of the ratio.
- To solve a proportion a:b = c:x, enter a, b and c and read x.
Examples
- 24:36 simplifies to 2:3.
- 3:5 = 12:20, so with 12 parts flour you need 20 parts water.
Good to know
Neither value in a ratio can be zero, and in a proportion a cannot be zero. The missing value is calculated as x = b × c ÷ a. For decimals, multiply both parts by the same power of ten first to make them whole numbers. A ratio compares parts to each other; a fraction compares a part to the whole.
Examples with screens, maps and recipes are in the ratio guide. For image shapes, see aspect ratio.
FAQs
Does simplifying change the meaning?
No. 24:36 and 2:3 describe exactly the same relationship.
How do I scale a recipe?
Use the proportion mode with one known pair of amounts and the new amount of one ingredient.