Parlay Tax Calculator
A parlay tax calculator reveals the hidden mathematical cost of combining bets into a parlay versus placing them as individual straight bets. Each leg you add compounds the sportsbook's vig, dramatically increasing the house edge. This calculator shows exactly how much extra you're paying by parlaying instead of betting each leg separately.
Formula
Parlay Tax = 1 - (Parlay EV / Sum of Individual Bet EVs)How to Use This Calculator
- Enter the odds for each leg of your planned parlay
- The calculator shows the combined house edge of the parlay
- Compare it to the house edge of betting each leg individually
- View the "parlay tax" — the extra cost of combining bets
When to Use This
- •Understanding the true mathematical cost of parlays
- •Comparing parlay returns to equivalent straight bets
- •Making informed decisions about when (if ever) to parlay
Parlay Tax Calculator
See how much expected value you lose by adding legs to your parlay. Understand the true cost of parlays.
Enter if your book shows different parlay odds than the calculated standard.
High parlay tax detected
This 3-leg parlay has a 13.0% tax. Look for profit boosts or parlay boosts to offset the tax.
Cumulative vig as you add each leg. Notice how the tax compounds exponentially.
Why Parlays Are a Tax
Every bet you place at a sportsbook includes a built-in fee called vig (or juice). On a standard -110/-110 market, the vig is about 4.5%. When you combine multiple bets into a parlay, this vig doesn't just add up — it compounds.
Think of it like sales tax stacking on top of sales tax. A 2-leg parlay at -110 per leg carries roughly 9% total vig. By the time you hit 5 legs, you're paying over 20%. At 10 legs, the “parlay tax” exceeds 40%.
This is why sportsbooks aggressively promote parlays — they're the most profitable product for the house. The longer your parlay, the bigger the edge the book has over you.
Parlay Tax Reference Table
Typical vig for standard -110 legs. All values assume symmetric -110/-110 markets.
| Legs | Cumulative Vig | Fair Odds | Book Odds | EV Loss / $100 |
|---|---|---|---|---|
| 2 | 8.9% | +300 | +264 | $35.54 |
| 3 | 13.0% | +700 | +596 | $104.21 |
| 4 | 17.0% | +1500 | +1228 | $271.67 |
| 5 | 20.8% | +3100 | +2436 | $664.09 |
| 6 | 24.4% | +6300 | +4741 | $1558.73 |
| 7 | 27.8% | +12700 | +9142 | $3557.57 |
| 8 | 31.1% | +25500 | +17545 | $7955.36 |
| 9 | 34.2% | +51100 | +33585 | $17514.77 |
| 10 | 37.2% | +102300 | +64208 | $38091.84 |
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For informational and educational purposes only. Not financial or gambling advice. All calculations assume odds remain constant and bets execute as entered. Actual results may vary. Gambling involves risk of loss.
Frequently Asked Questions
Why are parlays bad for bettors?
Parlays compound the sportsbook's vig on every leg. A 2-leg parlay at -110/-110 has a 9.1% house edge vs. 4.5% on each straight bet. A 5-leg parlay's effective house edge can exceed 20%. Sportsbooks promote parlays heavily because they're far more profitable for the house.
Are same-game parlays worse than regular parlays?
Same-game parlays (SGPs) are typically worse because the sportsbook controls the correlation pricing. With regular parlays across independent events, you can shop for the best odds on each leg. With SGPs, you're locked into one book's pricing and correlation adjustments.
Related Glossary Terms
Parlay
A single bet combining two or more selections where all must win for the bet to pay out.
ROI (Return on Investment)
Your net profit divided by total amount wagered, expressed as a percentage.
Expected Value (EV)
The average amount you can expect to win or lose per bet over time.
Bankroll Management
The practice of managing your gambling funds to minimize the risk of going broke.