Ratio Calculator
Calculate ratios, proportions, and scale factors. Simplify ratios, solve proportions, and convert ratios to fractions and percentages. Perfect for math problems and real-world applications.
Ratio Calculator
Ratio Results
Enter values to calculate ratio
About the Ratio Calculator
Our free ratio calculator simplifies ratios, solves proportions (find the missing value), calculates scale factor, and converts ratios to fractions and percentages. Ratios compare two or more quantities (e.g. 3:2 or 4:6:8). Use it for recipes, scale drawings, finance, and maths. Simplify to lowest terms, solve A:B = C:D for the unknown, or express the ratio as a fraction or percentage. For percentages alone, use our percentage calculator. For fractions, try our fraction calculator.
Frequently Asked Questions About Ratios
How do I simplify a ratio?
Divide both parts by their greatest common divisor (GCD). For example, 6:9 simplifies to 2:3. This calculator does it automatically.
What is a proportion?
A proportion is an equation of two equal ratios (e.g. A:B = C:D). If you know three values, you can find the fourth. Choose "Solve Proportion" and enter the known values.
How do I convert a ratio to a percentage?
Use the ratio as a fraction (e.g. 3:4 → 3/4) and multiply by 100. So 3:4 = 75%. The calculator shows this when you choose "Convert Ratio".