Ratio Calculator
Simplify a ratio and solve a missing value in a proportion.
Simplify a ratio
Enter the two non-zero terms of a ratio. The calculator divides both terms by their greatest common factor and keeps the relationship in the same order. Label the terms when the ratio describes a real measurement.
Proportions
A proportion states that a divided by b equals c divided by d. Cross multiplication can find a missing term when the known values describe the same relationship. Keep the units aligned before using a ratio.
Worked example
A ratio of 12 to 18 simplifies to 2 to 3 because both terms divide by 6. The order matters: 2:3 is not the same as 3:2.
Frequently asked questions
Frequently Asked Questions About Online Calculators
Can a ratio include decimals?
Convert to a consistent scale first, then simplify when an integer ratio is required.
Can I reverse the ratio?
Yes, but reversing changes the meaning and should be labeled clearly.
Does the calculator include units?
The math result is numeric; keep the source units in your own labels.