How it works
Fill in the 3 fields above and Proportion Solver calculates the result instantly, recalculating as you change any value. It applies the formula a/b = c/x → x = b·c / a. The math runs locally in your browser — nothing is sent to a server.
Formula
a/b = c/x → x = b·c / aExamples
- a 2, b 3, c 8 → x: 12
Frequently asked questions
How do I use the Proportion Solver?
Enter your values in the 3 input fields and the result is calculated automatically as you type. Change any value to see the numbers update instantly.
What formula does the Proportion Solver use?
It uses a/b = c/x → x = b·c / a. The calculation is performed in your browser using standard, well-established math for accurate results.
Is my data private?
Yes. The Proportion Solver runs entirely in your browser. Nothing you enter is uploaded, saved to a server, or shared — it never leaves your device.
Is the Proportion Solver free?
Yes, it is completely free with no sign-up, no limits and no watermarks. Like every tool on math and the rest of the platform, you can use it as often as you like.
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