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+398 Odds Explained

Decimal
4.98
American
+398
Fractional
199/50
Implied probability
20.08%
Polymarket
20¢
$100 wins
398.00
Inputs
Results
Decimal odds4.980
American
+398
Fractional
199/50
Implied probability
20.08%
Polymarket
20¢
Profit
398.00
Total return
498.00

4.980 decimal, +398 American, 20.08% implied probability

American odds of +398 mean

a 100 stake wins 398

. In decimal notation that is 4.98, in fractional notation 199/50, and the implied probability is 20.08%. On a prediction market the same price is a 20¢ share.

What +398 pays

A 100 stake at +398 returns 498.00 in total: your 100 back plus 398.00 profit. To win exactly 100 you would stake 25.13. The table covers the stakes people actually use.

Payout by stake
StakeProfitTotal return
1039.8049.80
2599.50124.50
50199.00249.00
100398.00498.00
5001,990.002,490.00
1,0003,980.004,980.00

Break-even and long-run results

The implied probability of +398 is 20.08%, and that number is also the break-even win rate: win more often than 20.08% 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
20%-0.4%
50%149.0%
55%173.9%
60%198.8%
65%223.7%

With an implied chance of 20.08%, a bet at +398 is expected to lose most of the time and to pay 398.00 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 +398

If both sides of a two-way market were priced at +398, the implied probabilities would add up to -59.84% above 100%. That excess is the overround, or vig; as a share of stakes it is a -149.00% 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.

+398 on a betting exchange

Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission +398 is worth 4.900 decimal (+390 American); at 5% it drops to 4.781 (+378). Those are the bookmaker prices you would need to beat.

Effective odds on an exchange
CommissionEffective decimalEffective AmericanBreak-even
2%4.900+39020.41%
5%4.781+37820.92%

Same price in other formats

Same price in other formats

Nearby prices

Nearby prices

  • +388 · 4.88 · 20.5%
  • +393 · 4.93 · 20.3%
  • +396 · 4.96 · 20.2%
  • +397 · 4.97 · 20.1%
  • +399 · 4.99 · 20.0%
  • +400 · 5.00 · 20.0%
  • +403 · 5.03 · 19.9%
  • +408 · 5.08 · 19.7%

Frequently asked questions

What does +398 mean in betting?

+398 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At +398 the implied probability is 20.08% and a 100 stake returns 498.00.

What is +398 in decimal odds?

+398 converts to 4.980 in decimal odds (usually shown as 4.98). Decimal odds are the total return per unit staked, so multiply your stake by 4.980 to get the return.

What is +398 as a fraction?

+398 is 199/50 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 +398?

A 100 stake at +398 wins 398.00 in profit and returns 498.00 including the stake. To win exactly 100 you would stake 25.13.

What win rate do I need at +398?

The break-even win rate equals the implied probability, 20.08%. Winning more often than that at this price is profitable over the long run; winning less often loses money.