Proportion & Cross Multiplication
Result
Proportion & Cross Multiplication — free online calculator.
Formula
- Proportion & Cross Multiplication calculates its result from a, b, c, d (0 = solve for d). It uses the formula a/b = c/d → d = b×c/a · Cross check: a×d = b×c. Change any input to recalculate the result instantly.
- The main inputs are a, b, c, d. Enter them in the units and format shown in the calculator.
- Keep comparable quantities in compatible units whenever the formula combines or compares them.
- Changing any input above recalculates the result with the same calculation engine used by this page.
Example: Proportion & Cross Multiplication
- a: 3
- b: 4
- c: 6
- d: 0 0 = solve for d
For a/b=c/d, solved d=b×c/a. A 0 in d input requests auto-solving; otherwise the cross products a×d and b×c are checked. Ratios on the result card use solved d.
Sample result: Calculating…
Frequently asked questions
What does the Proportion & Cross Multiplication calculate?
Proportion & Cross Multiplication — free online calculator.
Which values should I enter?
Enter a, b, c, d using the units and format shown beside each field.
What formula does this calculator use?
The calculator uses the following relationship: a/b = c/d → d = b×c/a · Cross check: a×d = b×c.
Why might my result differ from another source?
Results can differ when another source uses different units, rounding rules, conventions or assumptions. Compare the inputs and definitions before comparing results.
Does the result update automatically?
Yes. Changing an input updates the result using the same calculation engine shown on this page.