EV and Value Bet Calculator

How to use this calculator

There are two ways to set the true probability of your bet. With "No-vig 2-way line", enter the prices both sides of a market are paying at a sharp book - the calculator strips out the bookmaker margin and gives the fair probability and fair odds for your side. With "My win % estimate", you type your own probability instead. Then enter the odds you can actually bet and your stake. The calculator returns your edge (expected value per unit), the expected value in money, and whether the bet is positive value. If your price is longer than the fair odds, the bet is +EV.

The terms, explained

• Vig (juice, margin) - the bookmaker's built-in edge. The two sides of a market add up to more than 100%, and the excess is the vig.
• No-vig fair odds - the prices after the margin is removed, so the two sides add up to exactly 100%. This is the best simple estimate of true probability.
• Edge - your expected profit per unit staked. A +5% edge means you expect to win 5 cents on the dollar over the long run.
• Expected value (EV) - the edge applied to your stake: how much the bet is worth on average.
• Value bet - any bet where your price is longer than the fair price, giving a positive edge.

How it is calculated

Removing the vig from a two-way line uses each side's implied probability, then rescales so they sum to one. The edge compares your price against that fair probability. It is pure arithmetic, so the tool never needs updating.

• Implied probabilityimp = 1 ÷ decimal odds
• No-vig fair probabilityfair = imp(your side) ÷ (imp A + imp B)
• Edge per unitedge = fair × your decimal odds − 1
• Expected valueEV = stake × edge

A positive edge means a value bet; zero is a fair price; negative means the bet loses money over time.