Guides ·
How to use Ratio Calculator
Ratio Calculator. Simplify, solve and scale ratios. Cross-multiply: if a:b = c:d then a × d = b × c, so d = b × c ÷ a.
The short answer
To simplify a ratio, divide both terms by their greatest common divisor: 16:24 becomes 2:3. ClickZM also solves proportions such as 2:3 = 10:x (x = 15) by cross-multiplication and splits a total in a given ratio.
It runs in your browser. What you enter is not uploaded.
How to use it
Enter your values in the fields; defaults show a worked example.
Pick the units or options that apply to you.
Read the result, which updates instantly as you type.
Check the formula note under the result to see exactly how it was worked out.
Limits worth knowing
How do I solve a proportion? Cross-multiply: if a:b = c:d then a × d = b × c, so d = b × c ÷ a.
How do I split money in a ratio? Divide the total by the sum of the parts, then multiply by each part. £100 in 2:3 is £40 and £60.