Ratio Calculator
Simplify any ratio A:B to its lowest terms, and optionally divide an amount fairly between the two parts.
Ratios describe how a whole is shared — ingredients in a recipe, profit between partners, marks across subjects — but raw ratios like 12:18 are hard to read. This free ratio calculator reduces any ratio to simplest form with the greatest common divisor, and divides any amount you enter into fair shares, with the working shown.
Enter the two ratio parts (and optionally an amount), then press Calculate Ratio.
How to use the Ratio Calculator
- Enter the two parts of your ratio as positive whole numbers.
- Optionally enter an amount of money to divide between the two parts.
- Press Calculate Ratio to see the simplified ratio and each fair share.
Ratio Calculator — FAQs
Is this ratio calculator free?
Yes, completely free with no signup and no limits. Simplify ratios and divide amounts as often as you like, and everything runs privately in your own browser, with nothing uploaded or saved, ever, at all.
How does ratio simplification work?
The tool finds the greatest common divisor of both parts — the largest number that divides both evenly — and divides each part by it. For example, 12:18 has a greatest common divisor of 6, so it simplifies to 2:3.
How is an amount divided by ratio?
The simplified ratio parts are added to get the total parts, then the amount is split proportionally. Dividing Rs 10,000 in the ratio 3:2 means 5 total parts: A gets 3/5 (Rs 6,000) and B gets 2/5 (Rs 4,000).
Why must the ratio parts be whole numbers?
Ratios in lowest terms are defined with whole numbers, and the simplification step needs integers to find the greatest common divisor. If your ratio has decimals, multiply both parts to remove them first — for example, use 25:15 instead of 2.5:1.5.