Rex says
The fast lane for the math you almost remember from school. Type the numbers, get the answer, move on with your day.
Try a scenario
Click to load — tweak from there.Inputs
Result
Total payout if it hits
$45.83
Profit if it hits
$20.83
Implied probability required
54.5%
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter prop odds (american).
- 2Enter stake ($).
- 3Read your total payout if it hits on the right — it updates as you type.
- 4Hit Share to keep the scenario or send it to someone.
About this calculator
Player and game props (will a quarterback throw for over 250.5 yards, will a specific event happen in a game) are usually priced at standard American odds just like a moneyline or spread, but bettors often skip the mental math and just look at whether the number 'feels' right. This calculator gives you the exact payout, profit, and implied probability for a single prop bet at whatever odds and stake you enter, so you can decide with the actual numbers instead of a gut feeling about a big round payout figure. Prop markets, especially player props, often carry wider vig than main game lines — some books hold 6-10% or more on props compared to roughly 4.5% on a standard -110 spread — because there's less sharp money and competitive pressure keeping the number honest. Knowing your exact break-even probability on a specific prop price matters more here than on mainstream lines, since the extra vig means you need a real edge just to offset the worse-than-standard pricing.
Worked example
Using the values the calculator loads with:
Inputs
- Prop odds (American): -120
- Stake: 25 $
Results
- Total payout if it hits: $45.83
- Profit if it hits: $20.83
- Implied probability required: 54.5%
What each field means
Inputs
- Prop odds (American)
- The prop odds (american) used in the calculation. Starts at -120 so you have a working example on load.
- Stake ($)
- The stake used in the calculation, measured in $. Starts at 25 $ so you have a working example on load.
Results
- Total payout if it hits
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Profit if it hits
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Implied probability required
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why do player props usually have worse odds than a spread bet?
Prop markets have far less betting volume and fewer sharp bettors correcting mispriced lines compared to a main spread or total, so books widen the margin to protect themselves from being picked apart. It's common to see props priced with 6-10%+ hold, meaningfully more than the roughly 4.5% hold on a standard -110/-110 two-way line.
Should I parlay several props from the same game together?
Same-game prop parlays often involve correlated outcomes (a QB's passing yards and his longest completion, for instance), and books price same-game parlays assuming some independence that doesn't fully hold, which can work for or against you depending on the specific correlation and how the book has adjusted its same-game parlay pricing.
Is a round-number payout, like exactly 2-to-1, a sign of a fair bet?
No — the payout multiplier tells you nothing about whether the price is fair relative to the true probability of the outcome. A clean 2-to-1 payout (+200) still implies a specific 33.3% break-even probability, and whether that's a good bet depends entirely on whether the real probability of the prop hitting is meaningfully above that number.
Accuracy and limitations
- Results are rounded for display; the underlying calculation keeps full precision.
- Very large or very small inputs may hit floating-point limits in the browser.
- Inputs outside the accepted range are clamped rather than rejected.
Related tools
Odds Format Converter (American, Decimal, Fractional)
Convert American, decimal, and fractional betting odds instantly.
Implied Probability Calculator
See the win probability a betting line is actually pricing in.
Expected Value (EV) Bet Calculator
Find the dollar EV of a wager given your true win probability.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Prop Bet Payout Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/prop-bet-payout-calculator
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/prop-bet-payout-calculator" target="_blank" rel="noopener">Prop Bet Payout Calculator — RevenueLab</a> (2026).</p>
Source: [Prop Bet Payout Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/prop-bet-payout-calculator) (2026).