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If Bet 100 How Much Do Win Calculator

If I Bet 100, How Much Do I Win? works out Decimal odds and American / moneyline odds from Odds, Odds format and Kelly fraction. The default figures on this page give profit if the bet wins of 150; change any entry and the result, the working and the sources update together.

Profit if the bet wins
150
Betting Odds Calculator
Decimal odds
2.5
American / moneyline odds
150
Fractional odds
3/2
Implied probability
40 %
Hong Kong odds
1.5
Indonesian odds
1.5
Malay odds
-0.666667
Total return (stake plus profit)
250
Break-even win probability
40 %
Worked out from Kelly, J.L. Jr (1956), "A New Interpretation of Information Rate", Bell System Technical Journal 35(4), 917-926 and 3 other sources.
This is an arithmetic tool, not betting advice. Bookmaker prices already carry a margin, so the long-run expected value of a bet at posted odds is negative unless you genuinely have an edge. Gamble only what you can afford to lose.

Your figures

Updates as you type
Formatting only. This does not change the calculation.
American (+150, -110), decimal (2.50), fractional (3/2) or a probability (40%).
Leave on automatic unless a bare number is ambiguous.
Multiply full Kelly by this. Half Kelly (0.5) keeps most of the growth with far less variance.

How this is worked out

2 steps
  1. Decimal price = 2.5, i.e. 150 American, 3/2 fractional, 40% implied.
  2. A stake of 100 returns 250 in total, a profit of 150.

Its 5 worked examples are re-run on every release, last on 15 September 2026. What changed

Sources and references

4 sources
Thorp, E.O. (2006), "The Kelly Criterion in Blackjack, Sports Betting and the Stock Market", Handbook of Asset and Liability Management, Elsevier
Fractional-Kelly practice and the variance argument for staking below full Kelly.
Cortis, D. (2015), "Expected values and variances in bookmaker payouts: a theoretical approach towards setting limits on odds", Journal of Prediction Markets 9(1), 1-14
Definition of the overround/vigorish and the multiplicative method of removing it.
Shin, H.S. (1993), "Measuring the incidence of insider trading in a market for state-contingent claims", The Economic Journal 103(420), 1141-1153
Background on why the sum of implied probabilities exceeds one in a real book.

What the If I Bet 100, How Much Do I Win? calculates

Converts between American, decimal, fractional and implied-probability odds, works out payouts and parlay returns, strips the bookmaker margin to give no-vig fair prices, finds arbitrage stakes across books, sizes a bet by the Kelly criterion and computes hedge stakes and martingale sequences.

How to use this If I Bet 100, How Much Do I Win?

Enter Odds, Odds format and Kelly fraction. Decimal odds updates as you type. Change one figure at a time to see what drives the result.

How the result is worked out

Open “How this is worked out” beside the result for the step-by-step calculation behind Decimal odds, American / moneyline odds and Fractional odds.

The method follows Kelly, J.L. Jr (1956), "A New Interpretation of Information Rate", Bell System Technical Journal 35(4), 917-926, Thorp, E.O. (2006), "The Kelly Criterion in Blackjack, Sports Betting and the Stock Market", Handbook of Asset and Liability Management, Elsevier, Cortis, D. (2015), "Expected values and variances in bookmaker payouts: a theoretical approach towards setting limits on odds", Journal of Prediction Markets 9(1), 1-14 and Shin, H.S. (1993), "Measuring the incidence of insider trading in a market for state-contingent claims", The Economic Journal 103(420), 1141-1153.

What you can compare

Change one input at a time to see how it affects Decimal odds, American / moneyline odds and Fractional odds. The inputs you can vary are Odds, Odds format and Kelly fraction.

Understanding Decimal odds, American / moneyline odds and Fractional odds

This is an arithmetic tool, not betting advice. Bookmaker prices already carry a margin, so the long-run expected value of a bet at posted odds is negative unless you genuinely have an edge. Gamble only what you can afford to lose.

Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.

Embed this calculator on your website

Copy this code into any page. The calculator appears with the figures currently entered, sizes itself to fit, and a small credit line links back here. Free, no account, no ads inside it, no tracking of your readers. Set your own figures and fixed fields; Personal removes the credit line, sets your colour and shows you which sites use it.

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Frequently asked questions

How much do you win on a $50 bet?

On the figures this page opens with, the profit if the bet wins is 150. No single number fits everyone: it follows Odds, Odds format and Kelly fraction, so enter your own above and the answer updates as you type.

How much money would you win if you bet $100 on the Super Bowl?

It needs Odds, Odds format and Kelly fraction. Nothing else is required, and the figures stay in your browser.

What does a $50 bet pay?

Converts between American, decimal, fractional and implied-probability odds, works out payouts and parlay returns, strips the bookmaker margin to give no-vig fair prices, finds arbitrage stakes across books. On this page it is computed from Odds, Odds format and Kelly fraction and shown as Decimal odds, American / moneyline odds and Fractional odds.

What information do I need for the If I Bet 100, How Much Do I Win??

You need Odds, Odds format and Kelly fraction. The page opens with default figures that give profit if the bet wins of 150, so you can see the scale before entering your own.

What does this If I Bet 100, How Much Do I Win? show?

It shows Decimal odds, American / moneyline odds, Fractional odds, Implied probability, Hong Kong odds, Indonesian odds, Malay odds and Profit if the bet wins, with the working and any warnings for your entries.

Can I check how the If I Bet 100, How Much Do I Win? result was calculated?

Yes. The “How this is worked out” section shows the calculation steps, and the sources section identifies the references used for the method.

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