Ratio Calculator
A ratio expresses the relationship between two quantities. The proportion A:B = C:D means that A×D = B×C (the cross-multiplication property). This calculator solves for any one missing term when the other three are known.
You can also simplify a ratio to its lowest terms by dividing both sides by their greatest common divisor (GCD). Ratios appear everywhere — in recipes, maps, finance, architecture, and mathematics.
How it works
A : B = C : D ⟹ A × D = B × C. To solve for a missing term, rearrange: e.g., D = (B × C) / A. To simplify A : B, divide both by GCD(A, B).
Use cases
- Scaling recipes up or down
- Solving proportion problems in math class
- Determining map or blueprint scales
- Mixing paint, cement, or chemical solutions in given ratios