Five calculators that do the arithmetic betting hides.
Almost every decision in sports betting comes down to a number the screen does not show you: what a price actually pays, the win rate it demands, the margin folded into it, the value of an edge, or the real chance a multi-leg slip has of landing. These five calculators produce those numbers instantly, they work the same way on football, basketball and baseball, and none of them asks you to sign in.
Type in a price in American, decimal, or fractional odds and a bet amount to see the total payout, the profit, and the implied probability.
Open calculator →Break-Even CalculatorTurn any American price into the win percentage it demands before it returns anything, plus the profit on a 100 dollar stake.
Open calculator →No-Vig CalculatorStrip the sportsbook margin out of a two-way market to reveal the fair probability, the fair price, and the hold the book was charging.
Open calculator →Expected Value CalculatorEnter a win probability, an American price, and a stake to see the expected value in dollars and as a percentage of what you risked.
Open calculator →Parlay CalculatorCombine up to twelve legs into a single price and see the total payout, the profit, and the implied probability of the whole slip.
Open calculator →They answer five different questions
The five tools are not alternatives to each other. The odds calculator comes first for anyone who is not yet fluent in a price: it just answers what a bet pays, in whichever format the price is shown. The next three sit in a sequence, each one taking the output of the last. A price arrives as something like -110, which tells you nothing about your edge until you convert it into the 52.38 percent win rate it is quietly demanding. That is the break-even calculator, and it is where every honest evaluation starts.
The no-vig calculator is the next step, and it is the one to reach for when you need a fair benchmark to judge your own number against, since the posted price always has the margin inside it. Once that margin is out you hold a fair probability rather than a posted one, and only then does an expected value figure mean anything. Using the raw implied probability of a posted price as your win probability is the most common way people convince themselves a bad number is a good one.
The parlay calculator sits slightly apart from the other three. It prices a slip rather than testing a single wager, and the figure worth watching on it is not the payout but the implied probability, because that is the number the payout is designed to distract from.
A price, a fair number, and the gap between
Take a two-way market priced at -110 on both sides. The break-even calculator says each side needs 52.38 percent. The no-vig calculator adds those two implied probabilities to 104.76 percent, rescales them, and returns a fair estimate of 50 percent per side, along with the roughly 4.5 percent the book holds. The gap between 52.38 and 50 is the entire cost of doing business at that price.
Now suppose your own read on that market is 55 percent. The expected value calculator turns your number and the offered price into a dollar figure, and the answer is positive, because 55 percent comfortably clears the 52.38 percent the price demands. Change your read to 51 percent and the same calculator returns a negative number, even though you still think you are on the right side. That gap between being right and being paid is what these tools exist to make visible. There is a fuller treatment of it in what is positive EV and in implied probability.
Guides that explain the math behind these tools.
The calculators are free. The edges are the product.
These four tools tell you what a price is worth. Membership tells you where the model disagrees with that price, across every board we publish, updated through the day.