Mathematics & Algebra • 100% In-Browser Computation
Ratio Calculator
Simplify ratios to simplest form or solve for unknown values in proportions (A : B = C : D).
How to Use the Ratio Calculator
Enter the required values in the fields above and click Calculate. All calculations are executed directly inside your web browser using proven mathematical formulas, ensuring instantaneous results and 100% privacy without transmitting your numbers to remote servers.
Mathematical Formula
A / B = C / D => A × D = B × C (Cross-multiplication)
Worked Example
To solve 4 : 5 = 20 : D => D = (5 × 20) ÷ 4 = 25.
Important Notes & Limitations
Ratio values must be non-zero real numbers.
Want an in-depth walkthrough? Read our full guide on How to Calculate and Simplify Ratios: Proportions & Scaling → with complete step-by-step examples and formula breakdowns.
Frequently Asked Questions
Find the greatest common divisor (GCD) of the terms and divide each term by that common factor.