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+840 Odds Explained

Decimal
9.40
American
+840
Fractional
42/5
Implied probability
10.64%
Polymarket
11¢
$100 wins
840.00
Inputs
Results
Decimal odds9.400
American
+840
Fractional
42/5
Implied probability
10.64%
Polymarket
11¢
Profit
840.00
Total return
940.00

9.400 decimal, +840 American, 10.64% implied probability

+840 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: 9.40 decimal, 42/5 fractional, 10.64% implied probability, 11¢ on Polymarket.

What +840 pays

A 100 stake at +840 returns 940.00 in total: your 100 back plus 840.00 profit. To win exactly 100 you would stake 11.90. The table covers the stakes people actually use.

Payout by stake
StakeProfitTotal return
1084.0094.00
25210.00235.00
50420.00470.00
100840.00940.00
5004,200.004,700.00
1,0008,400.009,400.00

Break-even and long-run results

The implied probability of +840 is 10.64%, and that number is also the break-even win rate: win more often than 10.64% 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
11%3.4%
50%370.0%
55%417.0%
60%464.0%
65%511.0%

With an implied chance of 10.64%, a bet at +840 is expected to lose most of the time and to pay 840.00 on 100 when it does not. Outright markets, correct scores and big upsets are where these prices appear, and they are the prices bookmakers shade the hardest.

The vig at +840

If both sides of a two-way market were priced at +840, the implied probabilities would add up to -78.72% above 100%. That excess is the overround, or vig; as a share of stakes it is a -370.00% 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.

+840 on a betting exchange

Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission +840 is worth 9.232 decimal (+823 American); at 5% it drops to 8.980 (+798). Those are the bookmaker prices you would need to beat.

Effective odds on an exchange
CommissionEffective decimalEffective AmericanBreak-even
2%9.232+82310.83%
5%8.980+79811.14%

Same price in other formats

Nearby prices

Nearby prices

  • +790 · 8.90 · 11.2%
  • +815 · 9.15 · 10.9%
  • +830 · 9.30 · 10.8%
  • +835 · 9.35 · 10.7%
  • +845 · 9.45 · 10.6%
  • +850 · 9.50 · 10.5%
  • +865 · 9.65 · 10.4%
  • +890 · 9.90 · 10.1%

Frequently asked questions

What does +840 mean in betting?

+840 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At +840 the implied probability is 10.64% and a 100 stake returns 940.00.

What is +840 in decimal odds?

+840 converts to 9.400 in decimal odds (usually shown as 9.40). Decimal odds are the total return per unit staked, so multiply your stake by 9.400 to get the return.

What is +840 as a fraction?

+840 is 42/5 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 +840?

A 100 stake at +840 wins 840.00 in profit and returns 940.00 including the stake. To win exactly 100 you would stake 11.90.

What win rate do I need at +840?

The break-even win rate equals the implied probability, 10.64%. Winning more often than that at this price is profitable over the long run; winning less often loses money.