This article gives a practical, math-first explanation of how does vegas odds work, focusing on what +100 represents in American moneyline notation. You will find simple formulas, conversions to decimal and fractional formats, worked payout examples, and clear decision checks. The goal is to make the core math feel routine so you can apply it to small practice stakes, model checks, and structured prediction scenarios without confusion. No prior technical background is required; the steps are simple and repeatable.

In American moneyline format, +100 means even money: profit equals the stake and total payout is double the stake.

Convert +100 to decimal by adding one to odds divided by 100, giving 2.00, and to fractional as 1/1 or evens.

Implied probability for +100 is 100 / (100 + 100) = 50 percent, the break-even point for that price.

how does vegas odds work: quick definition of +100 odds

The phrase how does vegas odds work is central to understanding American moneyline notation, and +100 is the classic example of even money in that system. In American moneyline format, +100 denotes that a successful $100 stake returns $100 profit and pays $200 total, stake plus profit, which is the basic definition most betting primers use Investopedia moneyline guide.

Put simply, +100 means you get back double your stake when the selection wins: you keep your original stake and receive an equal amount as profit. That parity between stake and profit is what people mean by even money or evens, and it is consistent across mainstream sportsbook education TheLines American odds guide.

Practice conversions with FundedPlays challenges

Use the short examples in this article to practice converting stakes and implied probability; try the calculator steps on a notepad and compare results before you stake real money or enter structured prediction challenges.

Explore Challenges

What the plus sign indicates

The plus sign before a number in American odds marks the underdog side or the outcome that pays more than the stake when it wins; at +100 that premium equals the stake itself. A concise explanation of the sign convention and its usage is available in basic moneyline references Investopedia moneyline guide.

Why +100 is called even money

Because the profit equals the stake at +100, it is called even money: wagering $50 at +100 returns $50 profit and $100 total payout, which mirrors the core definition of evens used in American and international odds education TheLines American odds guide.

Moneyline basics: what the plus and minus mean

Moneyline is the American odds system that uses a plus sign for underdogs and a minus sign for favorites, and it is the standard notation in U.S. listings for single-outcome lines. This convention helps bettors see at a glance which outcome requires a larger risk to win a given amount and which pays more for the same stake Investopedia moneyline guide.

When a line shows a minus sign, such as -150, that tells you how much you must stake to win $100 profit; when it shows a plus sign, such as +100, it shows how much profit you would get on a $100 stake. This symmetry simplifies comparisons and the conversion to implied probability, as outlined in practical betting math resources Investopedia implied probability guide.

Bookmakers apply the same format across markets, so whether you are looking at a head-to-head listing or a prop market, the plus and minus signs carry the same arithmetic meaning. That consistency makes it easier to compare prices across events and providers TheLines American odds guide.

How to read a moneyline

Reading a moneyline requires identifying the sign and then applying the appropriate formula to calculate profit or stake equivalents; positive odds use one formula and negative odds use another. Clear walkthroughs of those formulas are provided in betting education materials that cover implied probability and conversions Action Network implied probability guide, and converters such as TheRundown can help you check examples.

When sportsbooks use plus versus minus

Sportsbooks show minus for favorites because those outcomes need a larger stake to yield a standard profit, while plus appears where the market is willing to pay more than the stake for a win. Market moves and bookmaker adjustments change specific numbers, but the sign convention remains steady across markets TheLines American odds guide.

Math of +100: how payouts and profit are calculated

For positive American odds the profit formula is Profit = Stake × (odds / 100). At +100 this simplifies because odds/100 = 1, so profit equals the stake. The formula and this simplification are standard and used in practical payout calculators Action Network implied probability guide.

Total payout is then Stake + Profit, which at +100 becomes Stake + Stake, or 2 times the stake. That doubling follows directly from the profit formula and is the reason decimal odds at +100 are 2.00, a point reinforced in odds conversion guides Caesars sportsbook guide.

Calculate total payout and profit from stake and odds

Enter stake and odds to get payout

Use the Profit formula to confirm: if Stake = $25 and odds = +100, Profit = 25 × (100/100) = 25, so Total Payout = 25 + 25 = 50. That stepwise math is the same computation any odds converter or calculator will perform when converting American odds to payout values Action Network implied probability guide. You can also try an implied probability calculator such as OmniCalculator to check these numbers.

Because the formulas are linear, they scale directly: doubling the stake doubles the profit at +100, and the decimal representation is simply the multiplier for total payout. Those conversion rules are taught across reputable betting education resources Caesars sportsbook guide.

Close up of calculator and small notepad showing example stakes and payouts $10 to $20 and $25 to $50 demonstrating how does vegas odds work in a minimalist Funded Plays color scheme

Write the profit formula as Profit = Stake × (odds / 100). For any positive odds number you plug that number in; for +100 the calculation becomes Profit = Stake × (100 / 100) = Stake. This exact algebraic simplification is a staple of payout math used by bettors and calculator tools Action Network implied probability guide.

Total payout calculation

Total payout equals Stake + Profit. At +100 that becomes Stake + Stake, or 2 × Stake, which is why the decimal odds form is 2.00 and why examples scale linearly with stake size Caesars sportsbook guide.

Converting +100 to decimal and fractional odds

Standard conversion for positive American odds is decimal = (odds / 100) + 1. For +100 that gives decimal = (100 / 100) + 1 = 2.00, which many odd conversion references confirm TheLines American odds guide.

Fractional odds at +100 are expressed as 1/1, often read aloud as evens, which matches the decimal 2.00 and the American +100 representation. Conversion tools and reference pages commonly list these equivalents to help users move between formats Pinnacle odds converter.

Standard conversion rules

To convert other positive American odds to decimal, apply the same formula: decimal = (odds / 100) + 1. This rule keeps conversions consistent and lets traders and bettors compare lines across formats quickly TheLines American odds guide.

Why conversions are useful

Decimal odds make it easy to compute total payout with a single multiplication, while fractional odds communicate profit relative to stake; converting +100 to 2.00 or 1/1 shows the same relationship in different notation systems and helps when you use international resources or calculators Pinnacle odds converter.

Implied probability and break-even at +100

The formula for implied probability with positive American odds is implied probability = 100 / (odds + 100). Plugging in +100 yields 100 / (100 + 100) = 0.5, or 50 percent, which is the mathematical break-even point for that price Investopedia implied probability guide.

That 50 percent figure means that if your own estimated chance of an outcome is greater than 50 percent, the +100 price represents positive expected value before fees and margins; if your estimate is lower, the price does not offer positive expected value. This interpretation is the basis for value checks and probability comparisons in betting education Action Network implied probability guide.

What does a +100 moneyline mean and how do I convert it to probability and payout?

A +100 moneyline is even money: profit equals stake and total payout is stake times two. Convert it to implied probability with 100 / (odds + 100) which yields 50 percent for +100, and to decimal by (odds / 100) + 1 which gives 2.00.

A useful reflection is: how confident are you, in percentage terms, that your pick will win? Comparing that number to the implied 50 percent is a simple way to decide if the +100 price offers value.

Probability formula for positive American odds

Rewriting the formula as a quick recipe helps: for positive odds X, implied probability = 100 / (X + 100). That short rule converts any positive American odds into a market-implied percentage and is widely cited in practical guides Action Network implied probability guide.

Why +100 equals 50% implied probability

Because the calculation is symmetric at +100, the market-implied break-even probability becomes exactly 50 percent; this symmetry is a helpful mental anchor when you compare your model or intuition to the public price Investopedia implied probability guide.

Worked examples: payouts at different stake sizes

Example 1, small stake: Stake = $10 at +100. Decimal is 2.00, so Total Payout = 10 × 2.00 = $20. Profit equals $10. This simple case confirms the doubling rule for +100 and matches standard payout examples TheLines American odds guide. You can verify with a free odds calculator such as Covers.

Example 2, common stake: Stake = $25 at +100. Profit = 25 × (100/100) = 25, and Total Payout = 25 + 25 = $50. Using decimal math: 25 × 2.00 = $50, the same result and an easy check for accuracy Action Network implied probability guide.

Example 3, odd cents: Stake = $123.45 at +100. Decimal multiplier 2.00 gives Total Payout = 123.45 × 2.00 = $246.90 and Profit = $123.45. Showing cents confirms that the math scales precisely regardless of stake size and that rounding follows normal currency rules TheLines American odds guide.

Small-stake examples

Start with small wagers to build confidence: $5 at +100 becomes $10 total, $2 at +100 becomes $4 total. Those tiny tests produce the same linear scaling and are quick ways to verify conversions on a calculator or spreadsheet Caesars sportsbook guide.

Odd stake examples with cents

When stakes include cents, multiply by 2.00 and round according to standard currency rounding. The arithmetic does not change and sample calculations remain a reliable way to check formulas before you stake larger sums TheLines American odds guide.

When you see +100 in markets: common scenarios

Markets show +100 in situations where two outcomes are judged roughly even by the market, such as evenly matched teams or balanced proposition lines; seeing +100 is a quick signal that the market has split probability roughly in half TheLines American odds guide.

Another common case is when a market moves and prices settle symmetrically, for example after heavy action on one side that pushes the other side to +100; the number itself remains mathematically even, though the market context can change the implied value Caesars sportsbook guide.

Funded Plays Challenges

Explore Challenges

Practically, seeing +100 in a prop or head-to-head listing should trigger the probability and bankroll checks described later, because while the raw math stays the same, margins and fees can affect whether the line offers positive expected value in your model TheLines American odds guide. See more about how we evaluate opportunities on our evaluations page.

Evens in moneyline listings

Evens are common in markets that expect a roughly 50/50 outcome, including coin-flip matchups or even props like a single event with two equally likely results; the +100 label provides a standard notation that is portable across lists and converters TheLines American odds guide.

Use cases in prop markets and head-to-head lines

In prop markets, +100 often appears where bookmakers want to split liability evenly or when liquidity is thin; in head-to-head lines, evens usually reflect balanced public or sharp opinion. The appearance of +100 should lead you to check your model rather than assume value Caesars sportsbook guide.

Decision criteria: when to take a +100 bet

Compare your own estimated probability to the 50 percent implied probability before staking on a +100 price. If your model or read of the matchup estimates a win probability greater than 50 percent, the line may represent value before fees and margins, a standard decision rule used in expected value checks Action Network implied probability guide. You can also review Funded Plays resources on the main site for related guidance Funded Plays.

A simple conceptual EV check is: EV = (your probability × profit) - ((1 - your probability) × stake). For +100 profit equals stake, so the math simplifies and you can see quickly whether expected value is positive based on your probability estimate and stake size Action Network implied probability guide.

Comparing implied probability to your model

If your model says 55 percent and the market is +100 (50 percent implied), you have a theoretical edge; if your model gives 45 percent, the market price is unfavorable. Use these comparisons as the primary filter for whether to risk a stake Action Network implied probability guide.

Bankroll and expected value check

Even when your probability estimate suggests value, size your stake relative to bankroll rules and risk tolerance: small, consistent stakes on positive EV opportunities preserve longevity and allow you to test whether your edge holds up over time Action Network implied probability guide.

Common mistakes and pitfalls to avoid

A frequent error is confusing profit with total payout; at +100 profit equals the stake, but total payout equals stake plus profit. Double-check whether a calculator or interface shows profit or total return to avoid misreading outcomes TheLines American odds guide.

Ignoring the bookmaker margin or vigorish is another common trap. Even if the market shows +100, the effective break-even can be slightly different once fees and margin are included, so always account for those costs in a fuller EV model Caesars sportsbook guide.

Avoid overconfidence from single-sample wins. Because +100 is a coin-flip equivalent in implied probability, a few wins or losses do not prove your forecasting skill; consistent edge requires repeatable advantage and disciplined bankroll management TheLines American odds guide.

How vigorish and market moves affect odds (brief note)

Vigorish, or the bookmaker margin, shifts the prices available in the market but does not change the arithmetic converting +100 to decimal or to implied probability; the formulas remain valid even when margins exist Caesars sportsbook guide.

Market moves can push a line to or from +100 as action comes in, and that movement reflects changing market beliefs or liability concerns rather than any change to the underlying math of payouts and implied probability TheLines American odds guide.

Quick checklist before placing a +100 bet

Three-step pre-bet checklist: 1) Confirm the conversion math (decimal 2.00, profit equals stake). 2) Compare implied probability 50 percent to your model probability. 3) Confirm the stake fits your bankroll rules. These quick checks reduce common entry errors and help maintain discipline Action Network implied probability guide.

Fast sanity checks also include verifying whether the platform shows profit or total payout and checking for fees or limits that could affect net outcomes. A short checklist prevents simple mistakes from costing more than they should TheLines American odds guide.

Glossary: key terms explained

American odds: The U.S. moneyline format using plus and minus signs to signal payout relationships. See general moneyline explanations for consistent definitions Investopedia moneyline guide.

Decimal odds: A format where total payout equals stake multiplied by the decimal number; +100 converts to 2.00, making payout math a single multiplication step Pinnacle odds converter.

Fractional odds: A ratio-style format used in some regions; +100 equals 1/1 or evens, indicating profit equals stake when the selection wins Pinnacle odds converter.

Implied probability: The market-derived probability calculated from odds; for positive American odds use 100 / (odds + 100), so +100 implies 50 percent Investopedia implied probability guide.

Stake, profit, payout: Stake is the amount you risk, profit is the net win if the selection succeeds, and payout is stake plus profit; at +100 profit equals stake and payout equals twice the stake TheLines American odds guide.

Summary and next steps

Key takeaways are simple: +100 equals even money, decimal 2.00, fractional 1/1, and implies a 50 percent break-even probability. Those equivalences let you convert stakes and probabilities quickly and reliably using the formulas shown earlier Action Network implied probability guide.

Next steps: practice the conversion with small stakes, compare your probability estimates to market-implied values, and use the checklist to keep staking disciplined. If you do structured prediction work or participate in skill-based challenges, apply these rules to your model validation rather than relying on short-run results TheLines American odds guide. For more reading and examples see our blog Funded Plays blog.

How much do I win on a $100 bet at +100?

A $100 winning stake at +100 returns $100 profit and $200 total payout, because profit equals the stake at even-money odds.

How do I convert +100 to probability?

Use the formula 100 / (odds + 100); for +100 this gives 100 / 200 = 0.5, or 50 percent implied probability.

Is +100 the same as decimal 2.00?

Yes, +100 converts to decimal odds of 2.00 and fractional odds of 1/1, meaning total payout is stake times 2.

If you want to practice, run the worked examples on paper or in a spreadsheet and compare decimal multipliers to the profit formula. Use the checklist before placing real stakes or when testing predictions in structured challenge platforms. Understanding that +100 is even money and implies a 50 percent break-even probability removes guesswork from conversion math and helps you focus on model quality and disciplined bankroll rules.