Separate two or more values with colons, commas, spaces, or semicolons.
How to use the ratio calculator
Simplify a multi-part ratio or solve a:b = c:x proportion.
Enter ratio values
Type two or more whole numbers separated by colons, commas, spaces, or semicolons.
Enter the proportion
For a:b = c:x, enter a, b, and c. The calculator finds x as a × c ÷ b.
Check the working
Read the common divisor and cross-multiplication working to confirm the result.
Frequently Asked Questions
How do I simplify a ratio?
Divide every value by the greatest common divisor shared by all values. For 12:18:30, divide by 6 to get <strong>2:3:5</strong>.
How do I solve a:b = c:x?
Multiply a by c and divide by b: <strong>x = a × c ÷ b</strong>.
What separators can I use?
Use colons, commas, spaces, or semicolons between ratio values.
Can ratios contain zero?
A ratio cannot contain only zeros, and the divisor in a proportion cannot be zero. Other zero values can be meaningful in a ratio.
What is the greatest common divisor?
The GCD is the largest whole number that divides every value in the ratio without a remainder.
Are equivalent ratios the same as simplified ratios?
Equivalent ratios describe the same relationship. A simplified ratio is the equivalent form with no common divisor greater than one.
Can the proportion result be a decimal?
Yes. The proportion solver accepts finite numbers and returns a decimal when the division is not exact.