How Does Moneyline Work? The Math Behind Every Straight Bet
How does moneyline work? 5 worked examples break down the math behind plus and minus odds, implied probability, and finding value in straight bets.
A moneyline bet is the simplest wager in sports betting: pick who wins. No point spreads. No totals. Just one side or the other. The number next to each team tells you two things: how much you risk, and how much you collect. Understanding how moneyline works is the foundation for every other bet type, from parlays to prediction market contracts.
The moneyline is also a price. And like any price, it can be fair or unfair. This guide shows you the math behind moneyline odds, how to convert them to real probabilities, and how to spot when a sportsbook is overcharging you. If you already know the basics, skip straight to the implied probability section where the actual edge lives.
What Moneyline Odds Mean
Moneyline odds in the US are expressed relative to $100. There are two formats:
Negative moneyline (-150): You risk $150 to win $100 profit. The minus sign means this side is favored. The bigger the negative number, the heavier the favorite.
Positive moneyline (+200): You risk $100 to win $200 profit. The plus sign means this side is the underdog. The bigger the positive number, the longer the shot.
The $100 baseline is just a reference point. You can bet any amount. The ratio stays the same.
Worked example: -150 favorite
You like the Chiefs at -150. You bet $75.
- Profit if they win: $75 / 1.5 = $50
- Total return: $75 + $50 = $125
- The formula: Profit = Stake / (|Moneyline| / 100) = $75 / 1.5 = $50
Worked example: +200 underdog
You like the Bengals at +200. You bet $50.
- Profit if they win: $50 x (200 / 100) = $100
- Total return: $50 + $100 = $150
- The formula: Profit = Stake x (Moneyline / 100) = $50 x 2.0 = $100
Run any moneyline through the Odds Converter to see the decimal equivalent, fractional equivalent, and implied probability instantly. For a deeper breakdown of all three odds formats, read the how to read odds guide.
Moneyline Implied Probability: The Real Information
The moneyline is not just a payout ratio. It encodes a probability. A -150 line implies the sportsbook thinks that side wins roughly 60% of the time. A +200 line implies roughly 33%. These numbers are the key to finding value.
Converting negative moneyline to implied probability:
Formula: Implied Probability = |Moneyline| / (|Moneyline| + 100)
Example: -150 → 150 / (150 + 100) = 150 / 250 = 0.600 = 60.0%
Converting positive moneyline to implied probability:
Formula: Implied Probability = 100 / (Moneyline + 100)
Example: +200 → 100 / (200 + 100) = 100 / 300 = 0.333 = 33.3%
Here is the catch. Add those probabilities: 60.0% + 33.3% = 93.3%. That should be 100%. The gap between 100% and the sum of implied probabilities is the vig. In this case the book is charging about 6.7 percentage points of overround. Strip out the vig with the De-Vig Calculator to find the true implied probabilities.
After removing vig (using the multiplicative method), the true probabilities become approximately 64.3% and 35.7%. That is the sportsbook's actual opinion. Everything else is margin.
For the full explanation of vig and how it works across different bet types, read What Is Vig?.
Moneyline Payout Table: Common Lines at a Glance
Here is a reference table for the most common moneyline odds, their implied probabilities (before vig removal), and payouts on a $100 bet:
| Moneyline | Implied Probability | Profit on $100 Bet | Total Return |
|---|---|---|---|
| -300 | 75.0% | $33.33 | $133.33 |
| -200 | 66.7% | $50.00 | $150.00 |
| -150 | 60.0% | $66.67 | $166.67 |
| -110 | 52.4% | $90.91 | $190.91 |
| +100 | 50.0% | $100.00 | $200.00 |
| +110 | 47.6% | $110.00 | $210.00 |
| +150 | 40.0% | $150.00 | $250.00 |
| +200 | 33.3% | $200.00 | $300.00 |
| +300 | 25.0% | $300.00 | $400.00 |
| +500 | 16.7% | $500.00 | $600.00 |
Notice the pattern: as the implied probability drops, the payout rises. That is the risk-reward tradeoff encoded in every moneyline. The Odds Converter shows these conversions for any line, including decimal and fractional equivalents.
Finding Value on the Moneyline
A moneyline is only worth betting if the true probability of winning exceeds the implied probability baked into the price. That difference is your edge.
Worked example: Is -130 on the Lakers worth it?
Step 1: Convert -130 to implied probability. 130 / (130 + 100) = 130 / 230 = 56.5%
Step 2: Estimate the true probability. Your model (or a sharp benchmark line) says the Lakers win 62% of the time.
Step 3: Calculate expected value with the EV Calculator. EV = (0.62 x $76.92) - (0.38 x $100) = $47.69 - $38.00 = +$9.69 per $100 risked
That is a +EV bet. The sportsbook is pricing the Lakers at 56.5%, but you believe (with evidence) they win 62% of the time. Over hundreds of bets, that gap compounds into profit. Read Expected Value Explained for the complete framework.
Worked example: Is +180 on the Knicks worth it?
Step 1: Convert +180 to implied probability. 100 / (180 + 100) = 100 / 280 = 35.7%
Step 2: Your model says the Knicks win 30% of the time.
Step 3: EV = (0.30 x $180) - (0.70 x $100) = $54.00 - $70.00 = -$16.00 per $100 risked
That is a -EV bet. The plus sign looks attractive, but the math says the Knicks do not win often enough to justify the price. Big underdogs feel exciting. The math does not care about feelings.
Moneyline vs Point Spread vs Prediction Market Prices
The moneyline is one of three common ways to price an outcome:
Moneyline: Prices the outright winner. You see -150 / +130 on a sportsbook like DraftKings. The payout depends on which side you take.
Point spread: Prices a handicapped outcome. The favorite must win by more than the spread. Point spreads are typically priced at -110 on both sides. Different math, same vig concept.
Prediction market contracts: Prices an outcome as a contract between $0.00 and $1.00. A $0.60 contract on Kalshi is equivalent to -150 moneyline odds (60% implied probability). The conversion is direct: contract price = implied probability. This makes prediction markets the cleanest expression of price because there is no format to decode.
Convert between all three formats using the Odds Converter. If you trade prediction markets, the Market Converter translates sportsbook odds directly into contract prices so you can compare lines across platforms.
Understanding moneyline math is the first step in a pipeline. Odds tell you the price. Vig analysis tells you how much you are overpaying. Expected value tells you whether the bet is worth taking. Kelly sizing tells you how much to risk. Each step feeds the next. Skip one and the whole system breaks.
Common Moneyline Mistakes
Chasing big plus lines. A +500 underdog pays 5x your stake. That sounds great until you realize the implied probability is 16.7%. If the true probability is 12%, you lose money long-term despite the flashy payout. Always convert to implied probability before evaluating.
Ignoring vig on heavy favorites. A -300 moneyline looks safe. You win 75% of the time. But after removing the vig, the true implied probability might be 72%. You are paying a 3-point premium for the privilege of risking $300 to win $100. Heavy favorites carry the highest vig in absolute dollar terms.
Comparing moneylines across formats without converting. A -110 American line is not the same value as 1.90 decimal. (It is 1.909 decimal.) Small rounding differences matter at volume. The Odds Converter Guide covers every conversion formula with worked examples.
Betting moneylines without checking the spread equivalent. Sometimes the moneyline on a slight favorite offers better expected value than the point spread. Sometimes it is worse. The only way to know is to convert both to implied probability and compare. Sharp bettors check both markets before placing any wager.
Frequently asked questions
- What does a -110 moneyline mean?
- A -110 moneyline means you risk $110 to win $100 profit. The implied probability is 52.4%. This is the standard price on point spread bets and the most common line in sports betting. The extra $10 over $100 is the sportsbook's vig.
- How do you calculate moneyline payouts?
- For negative odds: Profit = Stake / (|Moneyline| / 100). For positive odds: Profit = Stake x (Moneyline / 100). A $50 bet at -150 pays $33.33 profit. A $50 bet at +200 pays $100 profit.
- Is moneyline the same as implied probability?
- Not exactly. Moneyline odds encode an implied probability, but they also include the sportsbook's vig. A -150 line implies 60% probability, but after removing vig the true implied probability might be 57-58%. Use a de-vig calculator to find the real number.
- What is the difference between moneyline and point spread?
- Moneyline bets are on who wins outright. Point spread bets are on the margin of victory. A team can lose the game but cover the spread. Moneyline odds vary by matchup (-300 to +500 or wider), while point spreads are typically priced at -110 on both sides.
- Can you convert moneyline odds to prediction market prices?
- Yes. A prediction market contract price equals the implied probability. Convert moneyline to implied probability (-150 = 60%), and that is the equivalent contract price ($0.60). The Market Converter tool on Market Math does this conversion instantly.