Ratio & Proportion Calculator
Simplify ratios, solve proportions such as a:b = c:x, and divide an amount in a given ratio.
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How to use
- Simplify a ratio by typing it with colons, such as 1920:1080.
- Solve a proportion by filling in three of the four values.
- Split an amount by entering the total and a ratio such as 2:3.
How it works
Ratios with decimals are scaled to whole numbers and divided by their greatest common divisor, so 1.5:2.5 becomes 3:5. Proportions are solved by cross-multiplication: if a:b = c:x then x = b × c ÷ a.
Limitations
- Ratios use non-negative numbers.
Privacy
Your text is processed entirely in this browser tab. Nothing is uploaded, logged or saved by this tool.
Local processing protects your data from being uploaded, but it cannot protect against a compromised device or malicious browser extensions.