Ratio Calculator
Solve proportions and scale ratios — find the missing value in A : B = C : D.
D (missing value)
20
Breakdown
- A : B simplified
- 3 : 4
- B / A as decimal
- 1.33
Last updated:
FAQ
How do I solve a proportion?
Cross-multiply: from A:B = C:D you get A×D = B×C, then divide to isolate whichever value is unknown.
How do I simplify a ratio?
Divide both terms by their greatest common divisor — 12:16 simplifies to 3:4.
When are ratios useful?
Recipes, map scales, mixing paint or fuel, and resizing anything while keeping proportions intact.
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