Ratio Calculator

A ratio indicates how many times one number contains another, expressing the relative size of two quantities. This calculator takes two numbers (A and B), simplifies them to their lowest terms using the greatest common divisor, and converts the relationship into a decimal and a percentage. Whether you are comparing ingredients in a recipe, scaling a map, analysing financial ratios, dividing a resource between two parties, or simplifying a mathematical expression, this tool gives you the simplified form and its decimal and percentage equivalents in one step. Results update instantly as you change either value, making it easy to experiment with different ratios and see how they compare. Values do not need to be integers — decimals are accepted for both A and B. A ratio percentage above 100% is perfectly valid and simply means A is larger than B, which is common in growth-rate contexts, profit margins, or any situation where the numerator exceeds the denominator. Seeing the simplified form alongside the percentage gives you both the proportional relationship and its intuitive numeric equivalent at a glance.

The calculator finds the Greatest Common Divisor (GCD) of A and B using the Euclidean algorithm — repeatedly replacing the larger number with the remainder of dividing the two until the remainder reaches zero. The GCD is the largest number that divides evenly into both A and B without leaving a remainder. Both A and B are then divided by the GCD to produce the simplified ratio in its lowest terms, meaning no further reduction is possible. For example, 10 and 25 share a GCD of 5, so the ratio simplifies from 10:25 to 2:5. The decimal representation is A ÷ B, and the percentage is that decimal multiplied by 100. When A equals B the result is always 1:1 and 100%. When A exceeds B the percentage is above 100%, which is valid and common in financial or growth-rate contexts. All three outputs are calculated simultaneously.