Ratio Calculator – Simplify and Solve Ratios Online
Simplify ratios and split a total in a given ratio.
About the Ratio Calculator
What is the Ratio Calculator?
A ratio calculator simplifies a ratio and can split a total amount into two parts in that ratio.
Why use this calculator?
Recipe proportions, mixing paints, sharing costs fairly and scaling designs all operate on ratios.
How to use it
- Enter the two parts of the ratio.
- Optionally enter a total to split.
- Read the simplified ratio, the split and the percentages.
Formula
Simplified by dividing both parts by their GCD.
The optional total is divided in the proportion a:b.
Frequently Asked Questions
How is a ratio different from a fraction?
Ratios compare two quantities directly (3:2); fractions express one quantity relative to a whole (3/5 of the total).
Can ratios include three parts?
Yes — proportions like 1:2:3 exist; this tool focuses on the two-part case.
What order of operations does this use?
It follows standard PEMDAS/BODMAS rules: parentheses, exponents, multiplication and division, then addition and subtraction.
How precise are the answers?
The calculator uses double-precision floating-point math (about 15 significant digits) and rounds the display. For exact symbolic results use dedicated algebra software.
Can I enter negative numbers or decimals?
Yes. Negative values, decimals and very large or small numbers are all supported unless a field says otherwise.
What does it mean if I get an error?
Errors usually mean an invalid input, such as division by zero or a negative value where only positives make sense. Check your entries and try again.
Is this calculator free to use?
Yes. Every calculator on this site is completely free, with no hidden fees, no subscriptions and no limits on how many times you can use it.
How accurate are the results?
We use standard, widely accepted formulas and calculate in your browser using double-precision arithmetic. Results are rounded for readability, so treat them as reliable estimates rather than a guarantee. Real-world factors can vary the true figure.
Can I add this calculator to my own website?
Yes. Open this calculator page and use the "Add to your website" box in the sidebar to copy a ready-made iframe snippet, then paste it into any HTML page.
Does it work on a phone or tablet?
Yes. The layout is fully responsive, so it works on desktops, laptops, tablets and mobile phones, and every input adapts to touch screens.