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The odds conversion and implied-probability reference: every format, every formula (2026)

2026 edition · 6 pages · PDF + Word · updated 2026-07-19

What this reference covers

  • The three formats and what each one literally means
  • Conversion formulas in all six directions, with worked lines
  • Implied probability from each format, and the fair (no-vig) adjustment
  • Overround / book-percentage math for two-way and multi-way markets
  • A quick-lookup conversion table for common prices
  • Rounding and half-cent traps that make a converted price disagree with the book

Download

Two formats, same content. The PDF opens a print-ready reference with a branded cover page; the Word file is editable if you want to annotate or extract formulas into your own notes.

// not an app download This is an educational reference document (PDF and Word), not a betting app, software, account, or picks service. Nothing here is installed and nothing places a bet. To run these calculations interactively, use the calculators; to read the same material as articles, see the guides.

FAQ

Is this a betting app or software download?
No. It is an educational reference document in PDF and Word form. It explains odds formats, conversion formulas and implied-probability math. Nothing is installed, nothing places a bet, and there is no account or software of any kind.
What formulas does the reference include?
Conversions in all six directions between decimal, fractional and American odds; implied probability from each format; the no-vig (fair) adjustment by proportional normalisation; and overround / book-percentage math for two-way and multi-way markets, each with worked lines.
Are the prices in the document real market data?
No. Every price and probability is an illustrative teaching example chosen to demonstrate a calculation. The document makes no claim about any real market, book or event.
// educational reference · 2026 edition · OddsCipher Desk