Ratio Calculator
Runs locally in your browser. Nothing leaves your device.Enter a ratio and instantly simplify, normalize, scale, or split a total.
Enter a ratio
Use integers, decimals, scientific notation, or simple fractions.
Name parts
Labels are text only. They do not convert units.
Scale or split
Edit the factor, total, or a target part. That value becomes the input and all others are calculated automatically.
How it works
- 1
Enter the ratio
Enter the two or three parts of the ratio, optionally with custom labels.
- 2
Set the scaling
Optionally edit the factor, target sum, or a target part to scale.
- 3
Copy the simplified and scaled result
Copy the simplified ratio, the scaled values, or all results.
Good to know
The ratio calculator simplifies and scales a single ratio with two or three parts directly in your browser. You can scale by factor, target sum, or target part; input accepts integers, decimals, scientific notation, and simple fractions.
Calculation runs locally in the browser. Important: this calculator simplifies and scales a single ratio — for problems like “A corresponds to B, C corresponds to D,” the rule of three calculator is the right choice. Labels are plain text and don't convert units.
Typical use cases
Simplify a ratio to its simplest form
Enter a ratio such as 8:12 to reduce it to the simplified form 2:3.
Scale a mixture to a target amount
Enter the mixing ratio and a target sum or target part to calculate the right amounts for a larger or smaller batch.
Tips for better results
Use the rule of three calculator for correspondence problems
If the problem is “A corresponds to B, how much does C correspond to?”, the rule of three calculator is the more suitable tool than this ratio calculator.
Shares of the whole only meaningful with the same unit
The display of shares of the whole is only meaningful if all parts are components of the same whole and in comparable units.
Features
Two or three parts
Work with simple two-part ratios or more complex three-part ones.
Scale by factor, sum, or part
Edit the factor, target sum, or a target part — the other values are calculated automatically.
Local calculation
Calculation happens directly in the browser, without transmission to a server.
Frequently asked questions
What's the difference from the rule of three calculator?
This calculator simplifies and scales a single ratio. For problems like “A corresponds to B, C corresponds to D,” the rule of three calculator is the right tool.
Are my inputs uploaded?
No. Calculation runs entirely locally in the browser.
More tools
Looking for another tool?
Every tool runs locally in your browser – no sign-up, no upload, and it works offline.