FREE TOOL
Ratio Calculator
Simplify ratios, scale them up or down, and find a missing value in a proportion.
Simplified Ratio
2 : 3
Why Use Our Ratio Calculator?
Three Calculation Modes
Simplify a ratio, scale it by a multiplier, or find a missing value in a proportion - all in one tool.
Auto-Simplification
The simplify mode reduces any ratio to its lowest terms using the greatest common divisor automatically.
Scale Any Ratio
Enter a ratio and a multiplier to instantly see the scaled version. Useful for recipes, maps, and engineering plans.
Solve Proportions
The missing value mode solves A:B = C:? so you can find unknown values in proportional relationships.
Instant Results
Results update as you type with no button to press. Switch between modes without losing your inputs.
100% Private
All calculation happens in your browser. No data is sent to any server.
Frequently Asked Questions
How do I simplify a ratio?
Select the Simplify tab, enter A and B, and the calculator reduces the ratio to its lowest terms automatically.
How do I scale a ratio?
Select the Scale tab, enter your base ratio A:B and a multiplier. The scaled ratio is calculated instantly.
How do I find a missing value in a proportion?
Select the Find Missing tab and enter A, B, and C to solve A:B = C:?. The missing fourth value is calculated and displayed.
What is a ratio used for?
Ratios are used in cooking (scaling recipes), maps (scale factors), finance (financial ratios), and many other fields where two quantities are compared.
Can I use decimal numbers in a ratio?
Yes. The ratio calculator accepts decimal inputs in all fields. Results are shown with appropriate decimal precision.
Is the ratio calculator free?
Yes. Completely free with no sign-up required.
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