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+397 Odds Explained

Decimal
4.97
American
+397
Fractional
397/100
Implied probability
20.12%
Polymarket
20¢
$100 wins
397.00
Inputs
Results
Decimal odds4.970
American
+397
Fractional
397/100
Implied probability
20.12%
Polymarket
20¢
Profit
397.00
Total return
497.00

4.970 decimal, +397 American, 20.12% implied probability

+397 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: 4.97 decimal, 397/100 fractional, 20.12% implied probability, 20¢ on Polymarket.

What +397 pays

A 100 stake at +397 returns 497.00 in total: your 100 back plus 397.00 profit. To win exactly 100 you would stake 25.19. The table covers the stakes people actually use.

Payout by stake
StakeProfitTotal return
1039.7049.70
2599.25124.25
50198.50248.50
100397.00497.00
5001,985.002,485.00
1,0003,970.004,970.00

Break-even and long-run results

The implied probability of +397 is 20.12%, and that number is also the break-even win rate: win more often than 20.12% 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%-0.6%
50%148.5%
55%173.4%
60%198.2%
65%223.1%

+397 is a longshot. The bookmaker prices the outcome at 20.12%, and the payout of 397.00 per 100 staked is the compensation for how rarely it lands. Longshots carry more margin than any other part of the market, which is why devigging methods disagree most at prices like this one.

The vig at +397

If both sides of a two-way market were priced at +397, the implied probabilities would add up to -59.76% above 100%. That excess is the overround, or vig; as a share of stakes it is a -148.50% 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.

+397 on a betting exchange

Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission +397 is worth 4.891 decimal (+389 American); at 5% it drops to 4.772 (+377). Those are the bookmaker prices you would need to beat.

Effective odds on an exchange
CommissionEffective decimalEffective AmericanBreak-even
2%4.891+38920.45%
5%4.772+37720.96%

Same price in other formats

Nearby prices

Nearby prices

  • +387 · 4.87 · 20.5%
  • +392 · 4.92 · 20.3%
  • +395 · 4.95 · 20.2%
  • +396 · 4.96 · 20.2%
  • +398 · 4.98 · 20.1%
  • +399 · 4.99 · 20.0%
  • +402 · 5.02 · 19.9%
  • +407 · 5.07 · 19.7%

Frequently asked questions

What does +397 mean in betting?

+397 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At +397 the implied probability is 20.12% and a 100 stake returns 497.00.

What is +397 in decimal odds?

+397 converts to 4.970 in decimal odds (usually shown as 4.97). Decimal odds are the total return per unit staked, so multiply your stake by 4.970 to get the return.

What is +397 as a fraction?

+397 is 397/100 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 +397?

A 100 stake at +397 wins 397.00 in profit and returns 497.00 including the stake. To win exactly 100 you would stake 25.19.

What win rate do I need at +397?

The break-even win rate equals the implied probability, 20.12%. Winning more often than that at this price is profitable over the long run; winning less often loses money.