Polymarket / quoting
Bookmaking Calculator
Enter your fair numbers, choose the odds format you want to work with, and the calculator spreads the target hold across every selection to show the quote you would actually post.
Inputs
Input format
Selection 1
Selection 2
Quoted market
Enter your fair numbers, then read the book-adjusted quote you would post.
Book: 104.50%
4.50%
Target hold
104.50%
Final implied book
| Selection | Fair % | Fair odds | Quoted % | Quoted odds | Edge vs fair |
|---|---|---|---|---|---|
| Yes | 48.00% | 48.00% | 50.16% | 50.16% | 2.16 pts |
| No | 52.00% | 52.00% | 54.34% | 54.34% | 2.34 pts |
How to use it
Start with fair percentages or fair odds, set the hold you want to charge, then add every selection in the market. This is useful for binary markets as well as bigger multi-runner books where you need to see how the final quote compares with your fair line.
For Polymarket-style work, implied percentage is usually the clearest input mode, but the calculator also accepts decimal, American and fractional formats so you can move between feeds more easily.