Ratio Calculator
Instantly simplify ratios, find equivalent values, and convert ratios to fractions, decimals, and percentages with our free math tool.
Calculate & Simplify Ratios
Enter your ratio values below to instantly see the simplified form, decimal equivalent, and scaled variations.
Ratio Solver & Simplifier
Enter your values to calculate the ratio properties.
1.5 : 2.5, the calculator will automatically convert it to whole numbers and simplify it to 3 : 5.
How it Works
Understanding ratio calculations
Find the GCD
The calculator finds the Greatest Common Divisor (GCD) of both numbers to reduce the ratio to its simplest whole-number form.
Convert to Decimal
It divides Value A by Value B to show the relationship as a single decimal number, useful for direct comparisons.
Calculate Percentages
It determines what percentage each part represents relative to the other part, providing context to the proportion.
Scale Equivalently
If you provide a new target for Value A, it uses cross-multiplication to find the exact equivalent value for Value B.
Common Ratios & Equivalents
A quick overview of frequently used ratios in math, design, and everyday life.
| Ratio | Simplified | Decimal | Common Use Case |
|---|---|---|---|
| 1 : 1 | 1 : 1 | 1.0 | Equal parts, square aspect ratio. |
| 1 : 2 | 1 : 2 | 0.5 | Halves, recipe scaling. |
| 2 : 3 | 2 : 3 | 0.667 | Standard photo print sizes (e.g., 4×6). |
| 3 : 4 | 3 : 4 | 0.75 | Classic TV and monitor aspect ratio. |
| 9 : 16 | 9 : 16 | 0.5625 | Modern smartphone and HD video. |
| 16 : 9 | 16 : 9 | 1.778 | Widescreen displays and YouTube. |
Ratio Calculator FAQ
Answers to the most frequently asked questions about ratios, proportions, and simplification.
A ratio is a mathematical relationship between two or more quantities, showing how much of one thing there is compared to another. It is typically written with a colon (e.g., 3:2) or as a fraction (3/2).
To simplify a ratio, find the greatest common divisor (GCD) of the numbers involved and divide both sides of the ratio by that number. For example, the ratio 8:12 simplifies to 2:3 by dividing both numbers by their GCD, which is 4.
You can calculate an equivalent ratio by multiplying or dividing both sides of the original ratio by the same non-zero number. For example, multiplying both sides of 2:3 by 5 gives the equivalent ratio 10:15.
A ratio compares two quantities (e.g., 1:2), while a proportion is an equation stating that two ratios are equal (e.g., 1:2 = 2:4). Proportions are often used to solve for an unknown value in a ratio.