math tool
Ratio Calculator
Simplify ratios and solve proportions instantly with this free ratio calculator.
Enter two whole numbers to reduce a ratio using the greatest common divisor.
resultreduced
1 : 2
simplified ratio
How it works
ratio mathIn simplify mode, the calculator finds the greatest common divisor of both numbers and reduces the ratio to its lowest terms. In proportion mode, it solves a:b = c:x using cross multiplication, which makes quick scale calculations and missing-value checks much easier.
Common uses
quick referenceSimplify ratios for recipes, classroom math, and visual scale comparisons.
Solve proportions when resizing designs, maps, drawings, and ingredient amounts.
Check equivalent ratios quickly without working through each step by hand.