This article explains how a money odds calculator interprets American moneyline odds and turns them into decimal odds, fractional odds, implied probabilities, and exact payout figures. The goal is to make conversions reproducible in a spreadsheet or simple tool and to show how to remove the bookmaker margin for fair comparisons. The explanations use clear formulas, short worked examples, and a compact cheat sheet you can copy. The approach is practical and focused on disciplined comparison rather than promising outcomes.

American moneyline odds show profit on a $100 stake when positive and the required stake to win $100 when negative.

Decimal odds give total return per unit staked, and profit equals stake times decimal minus one.

Remove bookmaker margin by normalizing implied probabilities so comparisons reflect fair chances.

Quick overview: What are American moneyline odds?

American moneyline odds are a common U.S. format that shows either how much profit a $100 stake would earn or how much you must risk to win $100; positive values indicate profit on a $100 stake and negative values indicate the stake required to win $100, a convention used widely in U.S. educational resources and industry glossaries Investopedia moneyline guide

American odds differ from decimal odds, which show total return per unit staked, and from fractional odds, which express the profit:stake ratio; knowing these relationships makes cross-market comparisons straightforward and reduces misunderstanding when you move between formats.

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Try the step-by-step conversions below with a simple calculator or spreadsheet to see how a money odds calculator turns American odds into probability and payout figures you can compare.

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Why this matters when comparing markets: decimal odds let you compare total returns directly, while fractional odds make profit ratios easy to read; American moneyline odds remain the standard display for many U.S. markets and learning the conversion rules helps you interpret prices consistently.

How to read moneyline odds in practice

Interpreting positive and negative numbers is simple once you remember the rule: a positive moneyline number shows the profit on a $100 stake, and a negative number shows the stake required to win $100. For example, +150 means a $100 stake would net $150 profit, while -200 means you must risk $200 to win $100; this convention is the standard U.S. interpretation used in industry glossaries American Gaming Association glossary

Everyday examples using real-style lines make verbalization clearer. Say a line reads +150, you can say "plus one fifty, $100 returns $150 profit"; when you see -200, say "minus two hundred, risk $200 to win $100". These short verbal cues reduce misreads when you scan boards or compare screens.

Example: +150, verbalized as "plus one fifty"; profit on $100 stake is $150.
Example: -200, verbalized as "minus two hundred"; risk $200 to win $100.

Converting American odds to decimal and fractional formats

Formulas for positive and negative American odds (money odds calculator)

Use fixed formulas to convert American odds to decimal odds: for positive American odds, decimal = 1 + (odds / 100); for negative American odds, decimal = 1 + (100 / |odds|). These conversions follow standard mathematical relationships and let you express the same price as a total return per unit staked Wikipedia odds entry odds converter

Stepwise, for a positive line like +150: compute decimal = 1 + (150 / 100) = 2.50. For a negative line like -200: compute decimal = 1 + (100 / 200) = 1.50. Once you have decimal odds you can also derive profit by subtracting 1 and multiply by stake.

convert American odds to decimal and compute profit

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How to get fractional odds from the profit:stake ratio: fractional odds express profit relative to stake. Convert decimal to fractional by taking decimal minus 1 for the profit ratio and expressing that as a reduced fraction. For +150, decimal 2.50 implies profit 1.50, which equals 3/2 in fractional form; for -200, decimal 1.50 implies profit 0.50, which equals 1/2 fractional.

Separate formulas apply for positive and negative moneyline lines. For positive American odds, implied probability = 100 / (odds + 100). For negative American odds, implied probability = |odds| / (|odds| + 100). Converting to implied probability lets you compare outcomes across markets on the same scale Investopedia implied probability guide free odds calculator

Worked example: for +150, implied probability = 100 / (150 + 100) = 100 / 250 = 0.40 or 40 percent. For -200, implied probability = 200 / (200 + 100) = 200 / 300 = 0.6667 or about 66.67 percent. Framing prices as probabilities helps you spot value and compare offers objectively.

How do I convert American moneyline odds to a probability and payout?

Convert American odds to decimal using the sign-specific formula, compute implied probability with the respective formula for positive or negative lines, then calculate profit as stake times decimal minus one; normalize probabilities to remove the bookmaker margin when comparing markets.

Try this: pick a line you saw earlier and compute the implied probability with the two formulas above; check whether the percentages across all outcomes add to more than 100 percent, which would indicate bookmaker margin.

How to calculate profit and total payout from odds

Core payout math uses decimal odds because decimal values directly represent the total return per unit staked. The primary formulas are: profit = stake × (decimal − 1) and total payout = stake × decimal. These provide exact values for net gain and the combined return of stake plus profit Wikipedia odds entry implied probability calculator

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To compute profit from an American line, first convert the line to decimal using the formulas above, then apply the profit formula. For example, with +150 and a $50 stake: decimal is 2.50, profit = 50 × (2.50 − 1) = 50 × 1.50 = $75, and total payout = 50 × 2.50 = $125.

Short second example: for -200 with a $30 stake, decimal is 1.50, profit = 30 × (1.50 − 1) = 30 × 0.50 = $15, and total payout = 30 × 1.50 = $45. These calculations are easy to automate in a spreadsheet or to compute with the calculator formula shown earlier.

Minimal vector infographic of three outcome bars before and after overround normalization showing rescaled bars summing to 100 percent for a money odds calculator on a Funded Plays dark background

Removing the bookmaker margin: overround and fair probabilities

Close up minimalist spreadsheet showing decimal conversion formula and profit calculation with highlighted cells in Funded Plays colors for a money odds calculator interface

Bookmakers typically price multiple outcomes so that the summed implied probabilities exceed 100 percent; that excess is the overround or bookmaker margin. Identifying and removing the overround gives a normalized set of fair probabilities you can use for apples-to-apples comparisons Wikipedia overround entry

Normalization method: 1) compute implied probability for each outcome, 2) sum those probabilities to get the market total, 3) divide each outcome's implied probability by the market total, and 4) multiply by 100 to get normalized percentages that sum to 100. This simple proportional rescaling removes the margin so you can compare the market-implied chances to your own estimates.

Why this matters: a line that looks attractive before removing overround may not be attractive after normalization, especially in markets with large margins. Normalized fair probabilities provide a clearer baseline for computing expected value and making disciplined choices.

Worked examples: step-by-step calculations using common lines

Example 1, a two-outcome event with +150 and -180. Step 1, convert to decimal: +150 -> 2.50; -180 -> 1 + (100 / 180) = 1.5556. Step 2, implied probabilities: +150 -> 100 / 250 = 0.40; -180 -> 180 / 280 = 0.6429. Step 3, sum of implied probabilities = 0.40 + 0.6429 = 1.0429 or 104.29 percent, which shows a 4.29 percent overround. Step 4, normalize each probability: fair +150 = 0.40 / 1.0429 = 0.3837 or 38.37 percent; fair -180 = 0.6429 / 1.0429 = 0.6163 or 61.63 percent. Use these normalized figures to compare to your own estimated probability and compute expected value.

In the same example, compute payout and profit for a $100 stake on +150: decimal 2.50, profit = 100 × 1.50 = $150, payout = 100 × 2.50 = $250. For -180 and a $200 stake, decimal 1.5556, profit = 200 × 0.5556 = $111.11, payout = 200 × 1.5556 = $311.11. Keep rounding consistent to avoid small presentation errors.

Example 2, a multi-outcome market such as a three-way match with lines +120, +250, and -110. Step 1, convert to decimal: +120 -> 2.20, +250 -> 3.50, -110 -> 1.9091. Step 2, implied probabilities: +120 -> 100 / 220 = 0.4545, +250 -> 100 / 350 = 0.2857, -110 -> 110 / 210 = 0.5238. Step 3, sum = 1.2639 or 126.39 percent, indicating a sizable overround. Step 4, normalize by dividing each implied probability by 1.2639: fair +120 = 0.4545 / 1.2639 = 0.3597 or 35.97 percent, fair +250 = 22.61 percent, fair -110 = 41.42 percent. After normalization you have a set of fair probabilities that sum to 100 percent and are easier to compare against your own model.

Note on rounding: present percentages to two decimal places for clarity, and when computing expected value use more precise intermediate values to reduce rounding error before final presentation.

Common mistakes and troubleshooting when using a money odds calculator

Rounding and presentation errors are frequent. Users sometimes round too early, which compounds when converting between formats and normalizing; keep intermediate values to reasonable precision and only round the final displayed figures to two decimal places or one decimal place for percentages.

Misreading negative odds and stake interpretation is another common error. Remember that negative values indicate the stake needed to win $100, not a negative probability; misapplying the positive-odds formula to negative lines will produce incorrect decimals and payouts, so always branch your calculation based on the sign of the American odds Investopedia moneyline guide

How to check your work: convert an American line to decimal, then compute profit using profit = stake × (decimal − 1) and verify total payout equals stake × decimal. If these two results do not match your initial expectations, re-check the sign handling and the division steps.

Practical decision criteria and use cases

When to use manual calculation versus a calculator: manual steps help learning and troubleshooting, while a calculator or spreadsheet is faster for repeated work. Use manual conversions to verify tool results and to understand where differences arise when you compare markets. See the Funded Plays homepage for our main site.

How to interpret fair probability differences for decision making: after normalization, a price advantage is meaningful if the market's fair probability is materially higher than your own estimated probability by an amount that exceeds your transaction costs and margin of error. Convert probabilities to expected value to quantify whether a decision is positive over time.

Remember that platform rules, bankroll management, and responsible participation should guide your actions. Use these calculations as tools for disciplined, repeated decision making rather than a guarantee of outcomes.

Conclusion and next steps

Recap the essential formulas: convert American odds to decimal using 1 + (odds / 100) for positive lines and 1 + (100 / |odds|) for negative lines; implied probability uses 100 / (odds + 100) for positive and |odds| / (|odds| + 100) for negative; profit = stake × (decimal − 1); remove overround by normalizing implied probabilities.

Checklist to apply what you learned: convert, compute implied probability, sum implied probabilities, normalize to remove overround, compare fair probabilities to your estimates, and verify calculations in a spreadsheet. Use responsible practices and do not treat market prices as guarantees. Read more on the Funded Plays blog.

Appendix: quick formulas and cheat sheet

Payout formulas to copy: profit = stake × (decimal − 1); total payout = stake × decimal. Overround removal: normalized probability = implied probability / sum of implied probabilities.

How do I convert a positive American moneyline to decimal odds?

For positive American odds, decimal = 1 + (odds / 100). This yields the total return per unit staked.

What is implied probability for a negative moneyline like -200?

For negative odds, implied probability = |odds| / (|odds| + 100). For -200 that equals 200 / 300 or about 66.67 percent.

How do I remove the bookmaker margin from a market?

Compute each implied probability, sum them, then divide each implied probability by the total to normalize them so they sum to 100 percent.

Use the formulas and the checklist to verify tool outputs and to compare multiple markets responsibly. These calculations support consistent, repeatable decisions and should be paired with sound bankroll management. If you build a spreadsheet from the cheat sheet, keep intermediate precision and verify rounding on final results.