Simplify ratios, solve proportions and scale ratios up or down.
A ratio compares two quantities. Simplifying divides both parts by their greatest common divisor. To solve a proportion A:B = C:D for D, cross-multiply: D = (B × C) ÷ A.
Simplified ratio
Simplified A:B = (A ÷ GCD) : (B ÷ GCD)
Proportion — solve for D
A:B = C:D → D = (B × C) ÷ A
Set the known ratio as A:B, put your new amount as C, and the calculator solves for the matching quantity D that keeps the proportion identical.
It expresses the same relationship using the smallest whole numbers. For example, 6:8 simplifies to 3:4.