⚖️ Ratio & Proportion Calculator
Simplify ratios, scale proportional values, and solve missing ratio terms.
Try the calculator
The values below are a working example. Change any field to recalculate instantly in your browser.
Equivalent ratios multiply or divide both terms by the same non-zero factor.
Equivalent ratios
| Scale | Ratio |
|---|---|
| ×1 | 2:3 |
| ×2 | 4:6 |
| ×3 | 6:9 |
| ×4 | 8:12 |
| ×5 | 10:15 |
Formula & Mathematical Logic
Ratio A:B = (A / GCD) : (B / GCD)
Computes exact mathematical outputs locally on your device with 0 network latency.
Step-by-Step Worked Example
Sample Scenario
Simplifying the ratio 12:18 yields 2:3. Solving 4:5 = 16:X yields X = 20.
Frequently Asked Questions (FAQ)
How does the Ratio & Proportion Calculator work?
The Ratio & Proportion Calculator applies the mathematical formula Ratio A:B = (A / GCD) : (B / GCD) to compute your inputs 100% locally in your web browser.
Is my personal or financial data private?
Yes. Calcixa operates on a 100% privacy-first zero-backend architecture. No data leaves your device.
CALCIXA PRACTICAL GUIDE
How to use the Ratio & Proportion Calculator
A ratio compares quantities by division and can be simplified by dividing integer terms by their greatest common divisor. The calculator also scales equivalent ratios and solves a missing term in a proportion.
Ratios are meaningful only when quantities are compatible and their order is preserved. A ratio of 2:3 is not interchangeable with 3:2, and measurements should be converted to common units before comparison.
Step-by-step
- Enter ratio terms in the same order as the statement.
- Choose simplify, solve A:B = C:X, or split a total in ratio A:B.
- Enter the C value for a missing-term problem or the total amount for a split.
- Verify a proportion by cross-multiplication or confirm that the two shares add to the original total.
How to read the result
- Simplify mode reduces the ratio and lists several equivalent ratios.
- Solve mode finds X by cross-multiplication and displays a cross-product check.
- Split mode divides a total into two proportional shares and verifies their sum.
Common mistakes to avoid
- Swapping the order of terms.
- Comparing centimetres directly with metres.
- Dividing by zero or simplifying rounded measurements too aggressively.
Important: Review important outputs before relying on them in a production, legal, or safety-critical workflow.
More questions about Ratio & Proportion Calculator
How do I solve A:B = C:X?
Cross-multiply and divide: X equals B multiplied by C, divided by A.
How is a total split in a ratio?
For A:B, the first share is total × A ÷ (A+B), and the second share uses B.
What makes two ratios equivalent?
Their corresponding quotients or cross-products are equal, subject to non-zero denominators.
Sources and methodology
Calcixa explains the model, assumptions, and limitations so you can verify the result. See our calculation and tool methodology for rounding, privacy, testing, and correction practices.
Maintained by the Calcixa product team. This page was last updated on 7 September 2026.