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bettingcalculator.us

Know your numbers.

Betting Calculator Free payout, vig, and what the fair price costs you

A free betting calculator with one habit the others do not have: every result shows what the bet pays and what that payout costs, side by side.

Enter a price and you get the return, the hold, the overround, and the fair price the same market would carry with no margin in it at all.

You get

To win
$90.91
Total return
$190.91

It costs

Hold
4.55%
Overround
4.76%
Fair price
+100
Cost
$4.55 per $100
Cost assumptions

One outcome’s odds cannot tell you what a market costs. The cost figures above model a two-outcome market that is exhaustive and mutually exclusive, priced at the odds you entered on one side and the odds below on the other. Fair odds come from proportional normalisation of the two implied probabilities.

Hold is the share of every dollar staked the market keeps. Overround is how far the two prices sum past a fair book. They are different numbers and the two are routinely quoted as if they were the same one. Neither is a fee charged to you, and neither is a guaranteed loss on any single bet.

A desk adding machine with its paper tape splitting into two ribbons of equal width, one green and one red.

What your payout is, and what that payout costs

The math the book runs

  • Standard bet01

    4.55%

    What the book keeps on a standard −110 bet.

  • Three-leg parlay02

    13.03%

    What it keeps on a three-leg parlay of those same bets.

  • $100 bonus bet03

    $32–$80

    What a $100 bonus bet is worth, depending on the price it is used at.

Every sportsbook price contains two numbers. The first is the one the book shows you: what the bet pays. The second is the one it does not, which is what that payout costs next to a market carrying no margin at all. A betting calculator that returns only the first number answers half the question, and it is the easier half.

Take the price at the top of this page. A $100 bet at −110 wins $90.91 and returns $190.91, and any betting payout calculator will tell you so. What it will not usually tell you is that when both sides of a market are priced at −110, the two implied probabilities add up to 104.76% rather than 100%, and the book keeps 4.55 cents of every dollar staked. The fair price for a coin-flip market is +100. You are being offered −110, and the gap between those two is the whole business.

The vig is where that gap lives, and the word is used loosely enough to cover two different measurements. 4.76% is the overround: how far the posted prices sum past a fair book. 4.55% is the hold: what share of the money staked the book expects to keep. A betting odds payout calculator that picks one and prints it under the other label is doing the thing this site exists to undo, so both appear on every result here, named.

It is also why every betting calculator on this site asks what the other side of the market is priced at before it shows a cost figure at all. Vig is a property of a market, not of a single price. A free betting calculator that reports a margin from one number is guessing, and the guess tends to flatter whoever is quoting it.

The compound effect

More legs, more vig: the price of a parlay

More legs. A bigger cut for the book.

Combining bets multiplies the payout. It also multiplies the margin, once per leg, and that is the part the payout figure hides. Three −110 legs pay +595. Priced without margin, the same three legs are worth +700. The book has moved from keeping 4.55% to keeping 13.03%, and nothing about the ticket looks any different.

By eight legs it keeps 31.08%. That is not a claim about whether parlays are a good idea; it is arithmetic about what they cost, and it is the same arithmetic whichever book you use.

One limit worth stating plainly. The decay above assumes the legs are independent, so the payouts multiply and the margins compound cleanly. A same-game parlay breaks that assumption, because its legs describe the same event and move together. Books price those correlations in directly, which is why a same-game ticket rarely pays what multiplying the individual prices would suggest. The figures here describe ordinary multi-game parlays, and a correlated ticket needs its own pricing; this table will not price it.

Explore the parlay calculator →See the full odds chart →

  • 2 legs 8.9%
  • 3 legs 13.0%
  • 4 legs 17.0%
  • 6 legs 24.4%
  • 8 legs 31.1%
What the book keeps, at standard −110 legs, assuming the legs are independent and the payout multiplies. Correlated legs in a same-game parlay are priced differently.

Questions about the numbers on this page

5 questions

01

Is this betting calculator free to use?

Yes. Every betting payout calculator here runs in your browser. Nothing is stored, nothing is sent anywhere, and there is no account to make. The formulas are printed alongside the results so you can check any figure by hand.

02

What is the difference between hold and vig?

In everyday use they are one word for the sportsbook’s margin. As measurements they differ. Overround is how far the posted prices sum past a fair book; hold is the share of each dollar staked the book keeps. On a −110/−110 market the overround is 4.76% and the hold is 4.55%. The relationship is fixed: hold equals overround divided by one plus overround.

03

Why does one price alone not tell me the hold?

Margin is a property of a market, not of a single price. −110 on its own could sit in a market with almost no margin or a great deal of it, depending on what the other side is priced at. That is why the calculator asks for the opposite outcome before it shows any cost figure, and why a betting odds payout calculator that reports a hold from one number is guessing.

04

Does the hold mean I lose that much on every bet?

No. Any single bet wins in full or loses in full. Hold describes the expected share of turnover a market retains across many bets at that price, which is why it is quoted per $100 staked rather than per ticket. A single result tells you nothing about it in either direction.

05

What does a fair price of +100 mean?

It is the price the two outcomes would carry if the margin were removed and their probabilities were scaled to sum to exactly 100%. For an evenly priced two-way market that is +100, or an even-money bet. Comparing the offered price with the fair price is the quickest way to see what a market is charging.