Ratio & proportion calculator

Simplify ratios to lowest terms and solve proportions step by step.

A ratio compares two quantities. 12:18 simplifies to 2:3 (divide both by GCF=6).

If a/b = c/d, then ad = bc (cross multiply). Used to solve: if 3 apples cost $2, how much for 12?

Part-to-part: boys to girls = 3:2. Part-to-whole: boys to total = 3:5. Equivalent ratios: 2:3 = 4:6 = 10:15.