Ratio calculator
A ratio of 1.5 : 2 is not stuck as a decimal; scaling both sides by ten gives 15 : 20, which reduces to 3 : 4. This tool does that automatically by working in whole numbers behind the scenes, which is why entering measured values with decimal places still produces a clean ratio rather than an unhelpful 0.75 : 1.
A ratio simplifies by dividing both sides by their greatest common divisor: 6 : 8 becomes 3 : 4. To solve a proportion A : B = C : x, multiply B by C and divide by A. To split by shares, divide the total by the sum of the parts.
How to work with ratios
The three modes cover almost everything ratios are used for. Simplifying puts a measured relationship into its clearest form. Solving a proportion is the scaling operation behind recipes, map scales, mixing paint and converting units. Splitting by shares is how profit, rent and inheritance get divided, and it is the one where the arithmetic most often goes wrong, because people divide by the number of shares rather than by their sum.
Questions
Divide both sides by their greatest common divisor. 6 : 8 divided by 2 is 3 : 4.
Cross-multiply. For 2 : 3 = 10 : x, x is 3 × 10 ÷ 2 = 15.
Yes, and it still reduces. 1.5 : 2 is the same as 3 : 4.
Add the parts, divide the total by that sum, then multiply by each part. For 2:3:5 out of 1000, one part is 100.
A ratio compares two quantities; a fraction is one quantity divided by a whole. 3 : 4 means 3 parts to 4, which is 3/7 of the total.