BLAKbets

Sportsbook margin calculator

Enter every outcome's odds for a two-way or three-way market. See the sportsbook margin and proportional no-vig prices.

Market
Combined probability 103,89%. Sportsbook margin: 3,89%.
Home (1) no-vig
2,60
probability 38,50%
Draw (X) no-vig
3,53
probability 28,31%
Away (2) no-vig
3,01
probability 33,19%

Pure maths. No sign-in needed. Amounts are in USD, just like the platform.

Let the scanner find your next opportunity

The calculator does the maths. BLAKbets finds the opportunities, with over 143 arbs detected daily, calculated stakes, freshness indicators and direct sportsbook links.

View plans

No trial period. See plans and prices on the homepage. Adults aged 18+ only.

Formula

How margin and no-vig odds are calculated

  1. 01

    Convert odds to probabilities

    For each outcome: probability = 1 / odds.
  2. 02

    Add the probabilities

    Margin = combined probability − 100%. Below 100% across sportsbooks means arbitrage.
  3. 03

    Remove margin proportionally

    No-vig probability = probability / total. No-vig odds = 1 / no-vig probability.

Example

Example: a 1X2 market

Questions

Frequently asked questions

What is sportsbook margin?

The amount by which combined implied probabilities exceed 100%. At 1.91 / 1.91 they total 104.71%, giving an overround of 4.71%.

What are no-vig odds?

Normalize implied probabilities to total 100%, then convert them back into odds. This removes margin proportionally; it doesn't reveal the true probabilities.

What does negative margin mean?

If the best prices across sportsbooks imply less than 100%, they form an arb. Calculate its stakes in the arbitrage calculator.

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