Positive EV Calculator

Written by: Brian Webb
Fact checked by Alex Windsor  
Updated: May 20, 2024

It’s time to outsmart the bookies with our positive EV calculator. Type in your stake, odds, and win probability, and in real-time, determine if the bet is worth making or not. Use this tool to take advantage of soft bookie lines and welcome bonus offers now!

Using Our Positive EV Calculator

To use our positive EV calculator and crunch your wager’s expected value instantly, simply:

  1. Enter your stake
  2. Type in the odds
  3. Enter the win probability of your bet

The stake is the amount you’re betting. So if you’re wagering £100 on Arsenal, then your stake is £100. The odds are what the bookie will pay if your wager wins. Finally, the win probability is the likelihood of your bet winning. For example, if you believe Man United are way too strong for Chelsea and think they win 9/10 times, then the win probability is 90%.

If the expected value is negative, then over the long term, you’ll lose every time you place that wager. However, if it’s positive, you can expect to profit. The exact figure reveals the amount on average you’ll win or lose per bet.

What Is Expected Value?

Expected value is the amount you can expect to profit or lose on each sports bet over the long term with the same odds and stake. A positive EV indicates a profit, while a negative EV reveals a loss. Ideally, you should only make positive EV wagers and look for bets with the highest EV possible.

How Do You Calculate Expected Value?

To calculate expected value, you use this simple formula: (Profit per wager) x (Probability of winning) x – (Loss per wager) x (Probability of losing).

Here is how it looks in practice. Let’s say you bet £100 on Manchester City (1.25) to beat Fulham (13.0), and a draw pays 7.0. Follow these steps to calculate EV:

  1. Multiply your stake  by Manchester’s odds – £100 x 1.25 = £125
  2. Calculate the implied probability for a Manchester City win – 1/1.25 = 0.80
  3. Calculate implied probability for a Manchester City loss or draw – 1/ 13 + 1/7 = 0.22
  4. Plug the numbers into the formula – (25) x (0.80) – (100) x (0.22) = -2

This means that over the long term, you can expect to lose £2 on every £100 bet you make on Man City beating Fulham at 1.25 odds.

Why Does Expected Value Matter?

Expected value reveals if your bet is profitable over the long term. You can use this tool to take advantage of incorrect lines set by bookies. In most cases, the bookmaker’s odds will have a negative expected value due to the baked-in juice or commission that bookies charge. In the above example of Manchester City against Fulham, it’s 2%.

That’s why the expected value betting strategy requires you to handicap sporting events yourself and then place a bet when you find a profitable difference between the sportsbook’s calculated implied probability and your own. For example, if you think Manchester actually has a 95% chance of winning and is still paying 1.25, you should take that bet because now the expected value has flipped from -2 to 1.75.

Our free Positive EV calculator at Betting Tools can help you get the expected value quickly and accurately.