How this instrument works
Moneyline odds are the American way of quoting a bet, always shown as a signed number. A positive figure like +150 is an underdog price: it shows the profit on a $100 stake, so +150 means a $100 bet profits $150 if it wins. A negative figure like -200 is a favorite price: it shows how much you'd need to stake to profit $100, so -200 means you must risk $200 to profit $100. The sign flips the meaning of the number entirely, which trips up a lot of people new to the format.
Both cases convert to decimal odds with a single formula, just split by sign: for positive moneylines, decimal odds equal 1 + (moneyline/100); for negative moneylines, decimal odds equal 1 + (100/|moneyline|). Either way, the result is the same total-return multiplier used everywhere outside the US — +150 and -200 both land on decimal odds you can directly compare, even though the moneyline numbers themselves look nothing alike.
Moneyline odds of exactly +100 and -100 both describe even money — a 50/50 proposition where profit equals stake — and both convert to decimal odds of 2.00. That's the pivot point of the whole system: positive numbers start climbing above +100 as an outcome gets less likely, while negative numbers grow more negative below -100 as an outcome gets more likely.
- Enter the signed number from the sportsbook into American/moneyline odds — a positive value like 150 for a +150 underdog price, or a negative value like -200 for a -200 favorite price.
- Read Decimal odds for the equivalent payout multiplier — multiply any stake by this number for the total return on a win, stake included.
- Use a positive number for underdog-style prices (profit per $100 staked) and a negative number for favorite-style prices (stake needed to profit $100).
- Moneyline odds cannot be zero; sportsbooks never quote a price at exactly 0, since it belongs to neither the positive nor negative convention.
Worked example — American odds of +150
Enter 150 into American/moneyline odds. Since 150 is positive, the instrument computes 1 + 150/100 and Decimal odds reads exactly 2.50 — the underdog branch of the formula.
A +150 price means a $100 stake profits $150 if it wins, for a $250 total return. Check it against the decimal figure: $100 x 2.50 = $250, the same total return either format predicts. That agreement is exactly what the +1 conversion guarantees — decimal odds always fold profit and stake into one number.
Questions
What does a moneyline of +150 mean?
It means a $100 stake profits $150 if the bet wins, for a $250 total return — $100 back plus $150 profit. Positive moneylines always describe an underdog price: the higher the number, the less likely the outcome and the bigger the payout per dollar risked. It converts to decimal odds of 2.50, as in this instrument's worked example.
What does a moneyline of -200 mean?
It means you must stake $200 to profit $100 if the bet wins, for a $300 total return. Negative moneylines always describe a favorite price: the more negative the number, the more likely the outcome and the smaller the profit relative to what's risked. It converts to decimal odds of 1.50.
Why do positive and negative moneylines use different formulas?
Because the American convention itself is split into two mirror-image scales around the 50/50 point. Positive numbers show profit per $100 staked, so they're divided by 100 and added to 1. Negative numbers show stake needed per $100 profit, so it's 100 divided by the (absolute) moneyline instead, then added to 1. Both branches meet exactly at ±100, which both convert to decimal odds of 2.00.
Why can't the moneyline be zero?
Because a moneyline of exactly 0 has no place in either the positive (profit-per-$100) or negative (stake-per-$100-profit) convention — sportsbooks never quote it, and the formula has no branch that applies. The instrument requires a nonzero signed value.
How is this different from the decimal-odds or implied-probability instruments on this site?
This instrument converts a signed American figure specifically; the decimal-odds instrument builds decimal odds directly from a probability percentage instead. Once you have a decimal odds result from either path, this site's implied-probability instrument converts that decimal figure back into a probability percentage, closing the loop between all three formats.
Is +100 the same as -100?
They describe the identical bet — even money, where profit equals stake — and both convert to decimal odds of 2.00. Sportsbooks sometimes display it either way, but +100 and -100 are simply the positive and negative conventions meeting at their shared pivot point rather than two different prices.