About the Ratio Calculator
Enter two terms to reduce a ratio to its simplest form, see it as a decimal, and — with a scale value — solve the proportion A : B = C : ? for the missing term. Useful for recipes, mixes, maps, and aspect ratios.
How it’s calculated
Simplify by dividing both terms by their greatest common divisor. Solve a proportion with ? = B ÷ A × C.
Example calculation
16 : 9 is already in lowest terms (about 1.78:1); scaling to a width of 32 gives a height of 18.
Frequently asked questions
How do I scale a ratio up or down?
Multiply or divide both terms by the same number. To find a specific matching value, use the proportion solver — enter the new value for one term and it computes the other.
Can a ratio be a fraction?
Yes — a ratio A:B is the same as the fraction A/B. 3:4 equals 3/4 equals 0.75.
This tool provides estimates for general informational and educational purposes only. Results are based on the values you enter and standard formulas, and may not reflect your specific circumstances.