Simplify ratios, find equivalent ratios, and solve proportion problems.
A ratio is a comparison of two quantities. Ratios are used everywhere — in recipes, maps, scale models, financial analysis, and everyday problem-solving. Our ratio calculator helps you simplify ratios, find equivalent ones, and solve proportion problems in seconds.
A ratio expresses how much of one thing there is compared to another. Written as A:B, it means "for every A of the first quantity, there are B of the second." For example, a ratio of 2:3 means for every 2 units of A, there are 3 units of B.
To simplify a ratio, divide both numbers by their Greatest Common Divisor (GCD). For example: 8:12 → GCD(8,12)=4 → 8/4 : 12/4 = 2:3. This is the simplest form of the ratio.
If A:B = C:D, then D = (B × C) / A. This is the cross-multiplication method. Example: 3:4 = 6:? → ? = (4 × 6)/3 = 8.