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+155 Odds Explained

Decimal
2.55
American
+155
Fractional
31/20
Implied probability
39.22%
Polymarket
39¢
$100 wins
155.00
Inputs
Results
Decimal odds2.550
American
+155
Fractional
31/20
Implied probability
39.22%
Polymarket
39¢
Profit
155.00
Total return
255.00

2.550 decimal, +155 American, 39.22% implied probability

+155 is an American price:

the plus sign marks an underdog, and the number is the profit on a 100 stake

. Every other format describes the same chance: 2.55 decimal, 31/20 fractional, 39.22% implied probability, 39¢ on Polymarket.

What +155 pays

A 100 stake at +155 returns 255.00 in total: your 100 back plus 155.00 profit. To win exactly 100 you would stake 64.52. The table covers the stakes people actually use.

Payout by stake
StakeProfitTotal return
1015.5025.50
2538.7563.75
5077.50127.50
100155.00255.00
500775.001,275.00
1,0001,550.002,550.00

Break-even and long-run results

The implied probability of +155 is 39.22%, and that number is also the break-even win rate: win more often than 39.22% 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
39%-0.6%
50%27.5%
55%40.2%
60%53.0%
65%65.7%

+155 is an underdog price: the bookmaker gives this outcome an implied chance of 39.22%, and the payout of 155.00 on 100 reflects it. Underdogs in this band are where public money and bookmaker margin often disagree, so it pays to compare prices across books before taking one.

The vig at +155

If both sides of a two-way market were priced at +155, the implied probabilities would add up to -21.57% above 100%. That excess is the overround, or vig; as a share of stakes it is a -27.50% 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.

+155 on a betting exchange

Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission +155 is worth 2.519 decimal (+152 American); at 5% it drops to 2.473 (+147). Those are the bookmaker prices you would need to beat.

Effective odds on an exchange
CommissionEffective decimalEffective AmericanBreak-even
2%2.519+15239.70%
5%2.473+14740.44%

Same price in other formats

Same price in other formats

Nearby prices

Nearby prices

  • +145 · 2.45 · 40.8%
  • +150 · 2.50 · 40.0%
  • +153 · 2.53 · 39.5%
  • +154 · 2.54 · 39.4%
  • +156 · 2.56 · 39.1%
  • +157 · 2.57 · 38.9%
  • +160 · 2.60 · 38.5%
  • +165 · 2.65 · 37.7%

Frequently asked questions

What does +155 mean in betting?

+155 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At +155 the implied probability is 39.22% and a 100 stake returns 255.00.

What is +155 in decimal odds?

+155 converts to 2.550 in decimal odds (usually shown as 2.55). Decimal odds are the total return per unit staked, so multiply your stake by 2.550 to get the return.

What is +155 as a fraction?

+155 is 31/20 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 +155?

A 100 stake at +155 wins 155.00 in profit and returns 255.00 including the stake. To win exactly 100 you would stake 64.52.

What win rate do I need at +155?

The break-even win rate equals the implied probability, 39.22%. Winning more often than that at this price is profitable over the long run; winning less often loses money.