About the Part-to-Part Ratio Calculator
Convert between part-to-part and part-to-whole ratios and find each part from a total.
Also known as: part to whole ratio, part to part, ratio parts of a total.
How to use this calculator
- Enter part a, part b, total (optional).
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
A : B → A : (A + B)
Worked example
Using the values pre-filled in the calculator above:
- Part A = 3
- Part B = 7
- Total (optional) = 50
the calculator returns:
- Part-to-part: 3 : 7
- A : whole: 3 : 10
- B : whole: 7 : 10
- A share of total: 15