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-303 Odds Explained

Decimal
1.33
American
-303
Fractional
33/100
Implied probability
75.19%
Polymarket
75¢
$100 wins
33.00
Inputs
Results
Decimal odds1.330
  • The fraction shown is the closest simple fraction to the odds rounded to 3 decimals, not an exact match.
American
-303
Fractional
33/100
Implied probability
75.19%
Polymarket
75¢
Profit
33.00
Total return
133.00

1.330 decimal, -303 American, 75.19% implied probability

The price -303 converts to 1.33 decimal odds and 33/100 fractional odds. Read as a probability it says the bookmaker prices this outcome at 75.19%, 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 75¢.

What -303 pays

A 100 stake at -303 returns 133.00 in total: your 100 back plus 33.00 profit. To win exactly 100 you would stake 303.00. The table covers the stakes people actually use.

Payout by stake
StakeProfitTotal return
103.3013.30
258.2533.25
5016.5066.50
10033.00133.00
500165.02665.02
1,000330.031,330.03

Break-even and long-run results

The implied probability of -303 is 75.19%, and that number is also the break-even win rate: win more often than 75.19% 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%-33.5%
55%-26.8%
60%-20.2%
65%-13.5%
75%-0.2%

A price of -303 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 -303

If both sides of a two-way market were priced at -303, the implied probabilities would add up to 50.37% above 100%. That excess is the overround, or vig; as a share of stakes it is a 33.50% 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.

-303 on a betting exchange

Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission -303 is worth 1.323 decimal (-309 American); at 5% it drops to 1.314 (-319). Those are the bookmaker prices you would need to beat.

Effective odds on an exchange
CommissionEffective decimalEffective AmericanBreak-even
2%1.323-30975.56%
5%1.314-31976.13%

Same price in other formats

Same price in other formats

Nearby prices

Nearby prices

  • -313 · 1.32 · 75.8%
  • -308 · 1.32 · 75.5%
  • -305 · 1.33 · 75.3%
  • -304 · 1.33 · 75.2%
  • -302 · 1.33 · 75.1%
  • -301 · 1.33 · 75.1%
  • -298 · 1.34 · 74.9%
  • -293 · 1.34 · 74.6%

Frequently asked questions

What does -303 mean in betting?

-303 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At -303 the implied probability is 75.19% and a 100 stake returns 133.00.

What is -303 in decimal odds?

-303 converts to 1.330 in decimal odds (usually shown as 1.33). Decimal odds are the total return per unit staked, so multiply your stake by 1.330 to get the return.

What is -303 as a fraction?

-303 is 33/100 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 -303?

A 100 stake at -303 wins 33.00 in profit and returns 133.00 including the stake. To win exactly 100 you would stake 303.00.

What win rate do I need at -303?

The break-even win rate equals the implied probability, 75.19%. Winning more often than that at this price is profitable over the long run; winning less often loses money.