-420 Odds Explained
- Decimal
- 1.24
- American
- -420
- Fractional
- 5/21
- Implied probability
- 80.77%
- Polymarket
- 81¢
- $100 wins
- 23.81
- American
- -420
- Fractional
- 5/21
- Implied probability
- 80.77%
- Polymarket
- 81¢
- Profit
- 23.81
- Total return
- 123.81
1.238 decimal, -420 American, 80.77% implied probability
American odds of -420 mean
you risk 420 to win 100
. In decimal notation that is 1.24, in fractional notation 5/21, and the implied probability is 80.77%. On a prediction market the same price is a 81¢ share.
What -420 pays
A 100 stake at -420 returns 123.81 in total: your 100 back plus 23.81 profit. To win exactly 100 you would stake 420.00. The table covers the stakes people actually use.
| Stake | Profit | Total return |
|---|---|---|
| 10 | 2.38 | 12.38 |
| 25 | 5.95 | 30.95 |
| 50 | 11.90 | 61.90 |
| 100 | 23.81 | 123.81 |
| 500 | 119.05 | 619.05 |
| 1,000 | 238.10 | 1,238.10 |
Break-even and long-run results
The implied probability of -420 is 80.77%, and that number is also the break-even win rate: win more often than 80.77% 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.
| Win rate | Return on stake |
|---|---|
| 50% | -38.1% |
| 55% | -31.9% |
| 60% | -25.7% |
| 65% | -19.5% |
| 81% | 0.3% |
A price of -420 is deep odds-on. Bookmakers quote it when an outcome is close to a formality, and the margin they take is proportionally large at this end of the market. Sharp bettors tend to look at the other side of such a market, or at the exchange, where the same favourite is often available a tick or two better.
The vig at -420
If both sides of a two-way market were priced at -420, the implied probabilities would add up to 61.54% above 100%. That excess is the overround, or vig; as a share of stakes it is a 38.10% 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.
-420 on a betting exchange
Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission -420 is worth 1.233 decimal (-429 American); at 5% it drops to 1.226 (-442). Those are the bookmaker prices you would need to beat.
| Commission | Effective decimal | Effective American | Break-even |
|---|---|---|---|
| 2% | 1.233 | -429 | 81.08% |
| 5% | 1.226 | -442 | 81.55% |
Same price in other formats
Nearby prices
Nearby prices
Frequently asked questions
What does -420 mean in betting?
-420 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At -420 the implied probability is 80.77% and a 100 stake returns 123.81.
What is -420 in decimal odds?
-420 converts to 1.238 in decimal odds (usually shown as 1.24). Decimal odds are the total return per unit staked, so multiply your stake by 1.238 to get the return.
What is -420 as a fraction?
-420 is 5/21 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 -420?
A 100 stake at -420 wins 23.81 in profit and returns 123.81 including the stake. To win exactly 100 you would stake 420.00.
What win rate do I need at -420?
The break-even win rate equals the implied probability, 80.77%. Winning more often than that at this price is profitable over the long run; winning less often loses money.