Proportion Calculator
Solve proportions of the form a/b = c/x. Enter any three values and the calculator finds the missing fourth value using cross-multiplication.
Leave one field empty to solve for it
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How to Use the Proportion Calculator
- Enter the numbers or values in the input fields.
- The result is calculated and displayed automatically.
- Review the step-by-step solution or detailed breakdown.
- Copy the result or adjust inputs for a new calculation.
Référence rapide
| De | Vers |
|---|---|
| 2 + 3 | 5 |
| 12 × 12 | 144 |
| √144 | 12 |
| 2¹⁰ | 1,024 |
| π | 3.14159 |
| e | 2.71828 |
Cas d'utilisation
- •Checking homework or exam answers quickly and accurately.
- •Verifying manual calculations in professional or academic work.
- •Learning mathematical concepts with instant visual feedback.
- •Performing quick computations during meetings or presentations.
Formule
A proportion states that two ratios are equal: a/b = c/d. Cross-multiplication gives a × d = b × c. To find the unknown, isolate it: x = (b × c) / a.
Questions fréquemment posées
What is a proportion?
A proportion is an equation stating that two ratios are equal. For example, 2/3 = 4/6 is a proportion. Proportions are used in scaling, map reading, recipe adjustments, and many real-world applications.
How does cross-multiplication work?
For a/b = c/d, multiply diagonally: a × d = b × c. Then solve for the unknown. This works because multiplying both sides by b × d eliminates the denominators.
Which value should I leave empty?
Leave exactly one of the four fields (a, b, c, or x) empty. The calculator will detect which value is missing and solve for it automatically.