Ratio Calculator
Simplify a ratio, scale it up or down, or solve for a missing value in a proportion, free and instant right in your browser.
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How to use this calculator
- Enter the two numbers.
- Press Calculate for the simplified ratio.
How it works
A ratio is simplified by dividing both numbers by their greatest common divisor (GCD).
Worked example
18 : 24. Both divide by 6, giving 3 : 4.
Common mistakes
- Not reducing the ratio to its simplest form.
- Mixing up the order of the terms — 3:2 isn't the same as 2:3.
Frequently asked questions
How do I simplify a ratio?
Divide both sides by their greatest common divisor — 8:12 becomes 2:3.
How do I scale a ratio?
Multiply both terms by the same number, or solve the proportion for the missing term.
How do I scale a ratio up or down?
Multiply or divide both sides by the same number. 3 : 4 doubled is 6 : 8 — the same ratio.
Related tools
- GCD & LCM Calculator
- Percentage Calculator
- Average (Mean) Calculator
- Proportion Calculator
- Decimal to Fraction Converter
- Dilution Ratio Calculator
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Cite this tool
Zerdly. (2026). Ratio Calculator. Retrieved from https://www.zerdly.com/tools/ratio-calculator/
Tip: Enter any known values to calculate the remaining results.
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