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-120 Odds Explained

Decimal
1.83
American
-120
Fractional
5/6
Implied probability
54.55%
Polymarket
55¢
$100 wins
83.33
Inputs
Results
Decimal odds1.833
American
-120
Fractional
5/6
Implied probability
54.55%
Polymarket
55¢
Profit
83.33
Total return
183.33

1.833 decimal, -120 American, 54.55% implied probability

American odds of -120 mean

you risk 120 to win 100

. In decimal notation that is 1.83, in fractional notation 5/6, and the implied probability is 54.55%. On a prediction market the same price is a 55¢ share.

What -120 pays

A 100 stake at -120 returns 183.33 in total: your 100 back plus 83.33 profit. To win exactly 100 you would stake 120.00. The table covers the stakes people actually use.

Payout by stake
StakeProfitTotal return
108.3318.33
2520.8345.83
5041.6791.67
10083.33183.33
500416.67916.67
1,000833.331,833.33

Break-even and long-run results

The implied probability of -120 is 54.55%, and that number is also the break-even win rate: win more often than 54.55% 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%-8.3%
55%0.8%
60%10.0%
65%19.2%

An implied probability of 54.55% makes -120 a near-even price. This is the natural home of handicap and over/under markets, where the bookmaker adjusts the line rather than the price and both sides are quoted a shade under 2.00 decimal.

The vig at -120

If both sides of a two-way market were priced at -120, the implied probabilities would add up to 9.09% above 100%. That excess is the overround, or vig; as a share of stakes it is a 8.33% 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.

-120 on a betting exchange

Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission -120 is worth 1.817 decimal (-122 American); at 5% it drops to 1.792 (-126). Those are the bookmaker prices you would need to beat.

Effective odds on an exchange
CommissionEffective decimalEffective AmericanBreak-even
2%1.817-12255.05%
5%1.792-12655.81%

Same price in other formats

Same price in other formats

Nearby prices

Nearby prices

  • -130 · 1.77 · 56.5%
  • -125 · 1.80 · 55.6%
  • -122 · 1.82 · 55.0%
  • -121 · 1.83 · 54.8%
  • -119 · 1.84 · 54.3%
  • -118 · 1.85 · 54.1%
  • -115 · 1.87 · 53.5%
  • -110 · 1.91 · 52.4%

Frequently asked questions

What does -120 mean in betting?

-120 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At -120 the implied probability is 54.55% and a 100 stake returns 183.33.

What is -120 in decimal odds?

-120 converts to 1.833 in decimal odds (usually shown as 1.83). Decimal odds are the total return per unit staked, so multiply your stake by 1.833 to get the return.

What is -120 as a fraction?

-120 is 5/6 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 -120?

A 100 stake at -120 wins 83.33 in profit and returns 183.33 including the stake. To win exactly 100 you would stake 120.00.

What win rate do I need at -120?

The break-even win rate equals the implied probability, 54.55%. Winning more often than that at this price is profitable over the long run; winning less often loses money.