➗Ratio Calculator
Solve a proportion A : B = C : X for the missing value.
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About this calculator
Free Ratio Calculator — solve a proportion A : B = C : X and find the missing value.
How to use
Enter your A, B, C above — the result updates instantly as you type or drag the sliders. It's free and needs no sign-up.
Frequently Asked Questions
What does the Ratio Calculator do? ▼
Solve a proportion A : B = C : X for the missing value.
How does the Ratio Calculator work out the answer? ▼
The Ratio Calculator applies the standard mathematical formula for this problem to the values you enter and returns the exact result instantly.
How do I use the Ratio Calculator? ▼
Enter your values using the input fields or sliders. The result updates instantly — no submit button needed. All calculations run in your browser.
Can I use the Ratio Calculator for homework or study? ▼
Absolutely. The Ratio Calculator is a great way to check your work and understand the steps. Try solving the problem yourself first, then compare with the calculator.
Is the Ratio Calculator free? ▼
Yes — completely free. No sign-up, no download, and no account required. Works in any browser.