Ratio Calculator
Solve proportions (A:B = C:?) and simplify ratios.
Solve proportions and simplify ratios. Given that A is to B as C is to X, the calculator finds X, and it also reduces your ratio to its lowest terms. It is useful for recipes, scale models, mixing solutions, map scales and finance — anywhere quantities must stay in proportion.
Everything is worked out in your browser, instantly.
Frequently asked questions
How do I solve a ratio?
Enter the known ratio A:B and the value C; the tool solves A:B = C:X for the missing value X.
How do I simplify a ratio?
The tool divides both numbers by their greatest common divisor to show the ratio in lowest terms, e.g. 12:8 becomes 3:2.
What can I use a ratio calculator for?
Scaling recipes, mixing ratios, model and map scales, aspect ratios, and splitting amounts proportionally.
Can it handle decimals?
Yes, it accepts decimal values and returns a decimal result for the missing term.