Break-even win rate calculator
The win percentage a price needs just to break even — and what your actual rate is worth.
Every price carries a win rate you must clear before you make a penny. At the standard −110 it is 52.38%, not 50% — and the gap between those two numbers is the entire business of betting.
Break-even win rate
52.38%
ROI at 55.0%
+5.00%
Win rate needed for 5.0% ROI
55.00%
ROI here is profit per unit risked at flat stakes, which is what makes it comparable across prices. Win 55% at these odds and you keep +5.00% of everything you put through; to reach 5.0% you would need 55.00%, a gap of 0.00 points.
Break-even and ROI at common prices
| Odds | Break-even | ROI at 50% | ROI at 52% | ROI at 55% | ROI at 58% |
|---|---|---|---|---|---|
| -200 | 66.67% | −25.00% | −22.00% | −17.50% | −13.00% |
| -150 | 60.00% | −16.67% | −13.33% | −8.33% | −3.33% |
| -130 | 56.52% | −11.54% | −8.00% | −2.69% | +2.62% |
| -120 | 54.55% | −8.33% | −4.67% | +0.83% | +6.33% |
| -110 | 52.38% | −4.55% | −0.73% | +5.00% | +10.73% |
| -105 | 51.22% | −2.38% | +1.52% | +7.38% | +13.24% |
| +100 | 50.00% | 0.00% | +4.00% | +10.00% | +16.00% |
| +120 | 45.45% | +10.00% | +14.40% | +21.00% | +27.60% |
| +150 | 40.00% | +25.00% | +30.00% | +37.50% | +45.00% |
| +200 | 33.33% | +50.00% | +56.00% | +65.00% | +74.00% |
Read the −110 row carefully: a 52% win rate is negative. Winning more than half your bets and still losing money is the most common way a losing season feels like an unlucky one.
Why the price matters more than the pick
Hold your handicapping still and change only the number you take. A 55% win rate returns +5.00% at −110 and +7.38% at −105 — nearly half again as much profit from identical opinions. That is what line shopping is actually buying, and it is why the gap between your price and the Guardian Line is worth more attention than any single result.
Parlays don’t raise the bar — they raise the price
A three-leg parlay of −110 legs needs 52.38% per legto break even, which is exactly what a single bet needs. The required accuracy does not move. What moves is the bookmaker’s cut: about 13.03% on that parlay against 4.76% on a single, because the vig compounds once per leg.
Related: EV calculator · no-vig & hold calculator · parlay calculator · bankroll calculator
Common questions
- What win rate do I need to break even at −110?
- 52.38%. That is the implied probability of the price, vig included. Win exactly that share of your bets at flat stakes and you finish level; anything below it loses money over time, however close it feels.
- Why isn't break-even 50%?
- Because a −110 bet risks 110 to win 100. The missing 10 is the vig, and it moves the bar from a coin flip to 52.38%. The whole job of a bettor is clearing that 2.38-point gap — not picking winners, but picking them slightly more often than chance.
- Is a 52% win rate profitable?
- At −110, no. 52% returns −0.73% of everything you risk, so a bettor winning 52% of their bets is losing steadily while feeling roughly break-even. At −105 the same 52% turns positive at +1.52%, which is the entire argument for shopping for a better price.
- How do I turn a win rate into ROI?
- ROI per unit risked is p × b − (1 − p), where p is your win rate and b is the profit on a winning unit. At −110, b is 0.909, so a 55% win rate returns 5.00%. Flat staking is assumed — that is what makes ROI comparable across different prices.
- What's a good ROI in sports betting?
- Sustained ROI above roughly 5% at standard prices is strong, and most long-term winners live between 1% and 5%. At −110 that 5% needs a 55% win rate. Treat any claim of 20%+ over a large sample with suspicion — at −110 that implies winning about 63% of bets.
- Do parlays need a higher win rate per leg?
- No, and this surprises people. A three-leg parlay of −110 legs needs 52.38% per leg to break even — exactly the same as a single bet. What changes is the hold: the book's margin on that parlay is about 13.03% against 4.76% on a single, because the vig compounds with every leg. Parlays are not harder to hit per leg; they are far more expensive.
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