Square Root Calculator
√n and simplified radical.
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Ratio Calculator
Solve a proportion A : B = C : D for the missing value and simplify any ratio.
leave one box empty to solve for it
Missing value
—
Solved from the proportion.
| Proportion | — |
|---|---|
| Simplified A:B | — |
| As a decimal | — |
| Scale factor | — |
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Enter your figures above to see the step-by-step working.
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How the Ratio Calculator Works
A ratio compares two quantities, and a proportion says two ratios are equal: A is to B as C is to D. If you know any three of the four values, the fourth is fixed — cross-multiply (A × D = B × C) and solve. Leave one box empty and this calculator fills it in, then shows the ratio simplified to its lowest terms.
Proportions are everywhere: scaling recipes, mixing paint or fuel, reading maps, resizing images and converting units. The simplified ratio and decimal make it easy to see the relationship at a glance.
A : B = C : D → A × D = B × C
Frequently Asked Questions
How do I solve a ratio or proportion?
Set it up as A : B = C : D, enter the three values you know, and leave the unknown empty. The calculator cross-multiplies to find it.
How do I simplify a ratio?
Divide both terms by their greatest common divisor. The calculator shows the lowest-terms form automatically, e.g. 8 : 12 becomes 2 : 3.
What is a proportion used for?
Scaling anything up or down — recipes, mixtures, maps, models and unit conversions all rely on keeping a ratio constant.
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