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-660 Odds Explained

Decimal
1.15
American
-660
Fractional
5/33
Implied probability
86.84%
Polymarket
87¢
$100 wins
15.15
Inputs
Results
Decimal odds1.152
American
-660
Fractional
5/33
Implied probability
86.84%
Polymarket
87¢
Profit
15.15
Total return
115.15

1.152 decimal, -660 American, 86.84% implied probability

The price -660 converts to 1.15 decimal odds and 5/33 fractional odds. Read as a probability it says the bookmaker prices this outcome at 86.84%, which is the share of the time you would need to win just to break even. A prediction market would quote the same chance as 87¢.

What -660 pays

A 100 stake at -660 returns 115.15 in total: your 100 back plus 15.15 profit. To win exactly 100 you would stake 660.00. The table covers the stakes people actually use.

Payout by stake
StakeProfitTotal return
101.5211.52
253.7928.79
507.5857.58
10015.15115.15
50075.76575.76
1,000151.521,151.52

Break-even and long-run results

The implied probability of -660 is 86.84%, and that number is also the break-even win rate: win more often than 86.84% of the time at this price and you profit in the long run, win less often and you lose. The table shows the return on stake at a few win rates, including the break-even rate itself.

Return on stake by long-run win rate
Win rateReturn on stake
50%-42.4%
55%-36.7%
60%-30.9%
65%-25.2%
87%0.2%

A price of -660 is deep odds-on. Bookmakers quote it when an outcome is close to a formality, and the margin they take is proportionally large at this end of the market. Sharp bettors tend to look at the other side of such a market, or at the exchange, where the same favourite is often available a tick or two better.

The vig at -660

If both sides of a two-way market were priced at -660, the implied probabilities would add up to 73.68% above 100%. That excess is the overround, or vig; as a share of stakes it is a 42.42% margin for the bookmaker. Removing it leaves fair odds of 2.00 decimal ( +100) on each side. Use the devig calculator to do the same for any market.

-660 on a betting exchange

Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission -660 is worth 1.148 decimal (-673 American); at 5% it drops to 1.144 (-695). Those are the bookmaker prices you would need to beat.

Effective odds on an exchange
CommissionEffective decimalEffective AmericanBreak-even
2%1.148-67387.07%
5%1.144-69587.42%

Same price in other formats

Same price in other formats

Nearby prices

Nearby prices

  • -710 · 1.14 · 87.7%
  • -685 · 1.15 · 87.3%
  • -670 · 1.15 · 87.0%
  • -665 · 1.15 · 86.9%
  • -655 · 1.15 · 86.8%
  • -650 · 1.15 · 86.7%
  • -635 · 1.16 · 86.4%
  • -610 · 1.16 · 85.9%

Frequently asked questions

What does -660 mean in betting?

-660 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At -660 the implied probability is 86.84% and a 100 stake returns 115.15.

What is -660 in decimal odds?

-660 converts to 1.152 in decimal odds (usually shown as 1.15). Decimal odds are the total return per unit staked, so multiply your stake by 1.152 to get the return.

What is -660 as a fraction?

-660 is 5/33 in fractional odds, the traditional bookmaker notation where the top number is profit and the bottom number is stake.

How much do I win on a 100 bet at -660?

A 100 stake at -660 wins 15.15 in profit and returns 115.15 including the stake. To win exactly 100 you would stake 660.00.

What win rate do I need at -660?

The break-even win rate equals the implied probability, 86.84%. Winning more often than that at this price is profitable over the long run; winning less often loses money.