Implied probability explained: converting American odds to percent
Implied probability is the chance a price represents, shown as a percentage. For negative odds divide the odds (without the minus sign) by itself plus 100; for positive odds divide 100 by the odds plus 100. So -150 is 60% and +150 is 40%.
It lets you compare a price with a past hit rate on the same scale.
The two formulas
- Negative odds (favorites): implied % = odds ÷ (odds + 100). Example: -250 is 250 ÷ 350 = 71.4%.
- Positive odds (underdogs): implied % = 100 ÷ (odds + 100). Example: +250 is 100 ÷ 350 = 28.6%.
Even money (+100 or -100) is exactly 50%. Use the absolute value of negative odds in the first formula.
Quick reference table
| American odds | Implied probability | |---|---| | -1000 | 90.9% | | -400 | 80.0% | | -250 | 71.4% | | -150 | 60.0% | | -110 | 52.4% | | +100 | 50.0% | | +150 | 40.0% | | +250 | 28.6% |
A worked example with real prices
On the morning of November 8, FanDuel's money line for Los Angeles Rams at Washington Commanders was Rams -235 and Commanders +194.
- Rams -235: 235 ÷ 335 = 70.1%
- Commanders +194: 100 ÷ 294 = 34.0%
Those add up to 104.1%, not 100%. The extra 4.1% is the book's built-in margin (the juice). To get the market's no-margin view, divide each by the total: Rams 70.1 ÷ 104.1 = 67.3% and Commanders 34.0 ÷ 104.1 = 32.7%. That adjusted pair is often called the fair probability.
The same step works on the spread. Rams -5.5 at -108 is 51.9% and Commanders +5.5 at -118 is 54.1%. Together that is 106.0%, so the margin is about 6%, and the no-margin view is 48.9% and 51.0%.
Comparing a price with a hit rate
DraftKings listed Kyren Williams' 60+ rushing plus receiving yards at -377 on the same morning. That converts to 377 ÷ 477 = 79.0%. ESPN box scores show he reached 60+ in 7 of his 8 games in 2026, or 87.5%. A hit rate above the implied probability is interesting, but with only 8 games it is a prompt to research, not a conclusion. A price can also be fair when the player's past was lucky. See what is a prop hit rate.
Converting back: percent to odds
If you want the American odds for a probability p: when p is over 50%, odds = -p ÷ (1 - p) × 100 (so 60% gives -150); when p is under 50%, odds = (1 - p) ÷ p × 100 (so 40% gives +150).
Mistakes to avoid
- Treating -110 as 50%. It is 52.4% because of the margin; both sides of a -110/-110 market together make 104.8%.
- Mixing up the sign. Plus odds do not use the odds in the numerator.
- Ignoring the margin. Always compare no-margin numbers when you compare two sources.
- Using one price as truth. FanDuel and DraftKings can differ, and prices move. Check both before the game.
For how unit size can be tied to price and confidence, see the bankroll guide. DARIMARKET's hit rates pages show FanDuel and DraftKings prices next to each player's record.
Another common question: How do you remove the margin from implied probability?
Add the implied percentages of both sides, then divide each side by that total. Rams -235 and Commanders +194 total 104.1%, so the Rams' no-margin figure is 67.3%.
Keep going: player hit rates, tonight's slate, the bankroll guide and the unit-size table.
21+. Education, not advice. Research, not picks: past results only, and prices move, so check FanDuel or DraftKings for the live number. If betting stops being fun, call 1-800-GAMBLER.
See every player's hit rates free for 24 hours at darimarket.us.
FAQ
How do you convert American odds to implied probability? For negative odds, divide the odds (ignoring the minus) by that number plus 100. For positive odds, divide 100 by the odds plus 100. Multiply by 100 for a percent.
What does -110 imply? About 52.4%. It is above 50% because the book builds a margin into both sides of the market.
What is implied probability versus true probability? Implied probability is what a price represents, margin included. True probability is unknowable before the game; no-margin math and hit rates are only estimates around it.