➗ Ratio Calculator — Simplify and Scale Ratios
Enter two numbers to simplify their ratio, or provide a third value to find the missing part of a proportion.
Input
Result
Details
Private by design. This tool runs entirely in your browser — nothing you enter or add is uploaded to any server.
How it works
- Enter the two numbers of the ratio.
- Choose simplify to reduce the fraction, or scale to solve for the missing value.
- Results update when you press Calculate. GCD is used for exact simplification.
Examples
- 12:18 simplifies to 2:3.
- If 3 parts sugar to 5 parts flour, and you have 150 g sugar, you need 250 g flour.
- Useful for mixing paint, scaling recipes or map scales.
Frequently asked questions
Is my data sent anywhere?
No. The calculation runs entirely in your browser.
Does it handle decimals?
Yes. It works with decimal numbers and simplifies where possible.
What is the scale mode?
Given A:B and a new value C for A, it calculates the corresponding D for B so the ratio stays the same.
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