Skip to content

-308 Odds Explained

Decimal
1.32
American
-308
Fractional
25/77
Implied probability
75.49%
Polymarket
75¢
$100 wins
32.47
Inputs
Results
Decimal odds1.325
American
-308
Fractional
25/77
Implied probability
75.49%
Polymarket
75¢
Profit
32.47
Total return
132.47

1.325 decimal, -308 American, 75.49% implied probability

-308 is an American price:

the minus sign marks a favourite, and the number is the stake needed to win 100

. Every other format describes the same chance: 1.32 decimal, 25/77 fractional, 75.49% implied probability, 75¢ on Polymarket.

What -308 pays

A 100 stake at -308 returns 132.47 in total: your 100 back plus 32.47 profit. To win exactly 100 you would stake 308.00. The table covers the stakes people actually use.

Payout by stake
StakeProfitTotal return
103.2513.25
258.1233.12
5016.2366.23
10032.47132.47
500162.34662.34
1,000324.681,324.68

Break-even and long-run results

The implied probability of -308 is 75.49%, and that number is also the break-even win rate: win more often than 75.49% 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%-33.8%
55%-27.1%
60%-20.5%
65%-13.9%
75%-0.6%

At 75.49% this is a heavy favourite. Prices this short appear when one side is expected to win comfortably: a top seed against a qualifier, a strong home team against a relegation candidate, or a moneyline in a game with a double-digit spread. The catch is the payout. You need to win more than 75.49% of these bets just to stand still, and one loss wipes out several wins.

The vig at -308

If both sides of a two-way market were priced at -308, the implied probabilities would add up to 50.98% above 100%. That excess is the overround, or vig; as a share of stakes it is a 33.77% 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.

-308 on a betting exchange

Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission -308 is worth 1.318 decimal (-314 American); at 5% it drops to 1.308 (-324). Those are the bookmaker prices you would need to beat.

Effective odds on an exchange
CommissionEffective decimalEffective AmericanBreak-even
2%1.318-31475.86%
5%1.308-32476.43%

Same price in other formats

Same price in other formats

Nearby prices

Nearby prices

  • -318 · 1.31 · 76.1%
  • -313 · 1.32 · 75.8%
  • -310 · 1.32 · 75.6%
  • -309 · 1.32 · 75.6%
  • -307 · 1.33 · 75.4%
  • -306 · 1.33 · 75.4%
  • -303 · 1.33 · 75.2%
  • -298 · 1.34 · 74.9%

Frequently asked questions

What does -308 mean in betting?

-308 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At -308 the implied probability is 75.49% and a 100 stake returns 132.47.

What is -308 in decimal odds?

-308 converts to 1.325 in decimal odds (usually shown as 1.32). Decimal odds are the total return per unit staked, so multiply your stake by 1.325 to get the return.

What is -308 as a fraction?

-308 is 25/77 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 -308?

A 100 stake at -308 wins 32.47 in profit and returns 132.47 including the stake. To win exactly 100 you would stake 308.00.

What win rate do I need at -308?

The break-even win rate equals the implied probability, 75.49%. Winning more often than that at this price is profitable over the long run; winning less often loses money.