What is a Ratio?
A ratio compares two quantities of the same kind. It answers 'how many times is one quantity compared to another.' Ratios can be written as A:B, A/B, or 'A to B'. They are used in recipes, map scales, financial analysis, mixing chemicals, photography, and countless other applications.
Ratio Simplification — GCD MethodA : B → (A ÷ GCD) : (B ÷ GCD)
Example: 12 : 8 → GCD(12,8) = 4 → 3 : 2
Example: 12 : 8 → GCD(12,8) = 4 → 3 : 2
Proportions — Finding Missing Values
A proportion states that two ratios are equal: A:B = C:D. If three values are known, the fourth can always be found by cross-multiplication:
Cross-MultiplicationA/B = C/D → D = (B × C) ÷ A
Example: 3:4 = 6:D → D = (4 × 6) ÷ 3 = 8
Example: 3:4 = 6:D → D = (4 × 6) ÷ 3 = 8
Real-World Ratio Examples
| Scenario | Ratio | Use |
|---|---|---|
| Recipe (flour:water) | 2:1 | Scaled cooking |
| Map scale | 1:50,000 | 1 cm = 500 m |
| Cement:sand:aggregate | 1:2:4 | Construction mixing |
| Aspect ratio HD | 16:9 | Screen dimensions |
| Golden ratio | 1:1.618 | Design & aesthetics |
Frequently Asked Questions
The ratio calculator solves ratio equations, simplifies existing ratios to their lowest terms, and finds missing values in proportions (A:B = C:D).
Enter your initial numbers in the simplification fields and calculate. The tool divides all values by their greatest common divisor (GCD) to show the simplest integer form.
Yes. By calculating ratios as decimals, you can easily determine which ratio is larger or verify if they form an equivalent proportion.
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