For example, a bonus with a three times rollover requirement means you must wager it three times before you are allowed to withdraw it as cash). For bonuses, you must bet until you either meet the rollover requirement or lose at the bookmaker and win at the exchange.

Browser extension for quick comparisons without leaving a sports page
Dedicated mobile apps for iOS and Android with clean interfaces
Responsive web design that works on all screen sizes
Customizable dashboard to pin favorite sportsbooks and leagues

My Bonus Rollover Guide gives full details. Again, input your stakes, odds and commission to get your lay stake.

Tool Name	Ease of Use (1-5)	Accuracy (1-5)	Speed (1-5)
Oddschecker	4.5	4.7	4.3
OddsPortal	4.0	4.8	4.0
BetExplorer	3.8	4.5	4.2
The Action Network	4.7	4.4	4.6

Some bookmaker promotions will return your initial stake (the ‘free’ one they give you), although most will not. If the promotion terms say your stake will be returned, check ‘Stake returned’ to adjust the calculations accordingly.

How to Convert Fraction Odds to Decimals

In the case of a 4/1 bet, your bet is £1 and if it is successful you will win £4. The total return on this bet would therefore be £5 (initial £1 stake plus £4 winnings). The probability of a 4/1 chance winning is 20% - based on his calculation 1 / (4 + 1) = 0.20 It is a matter of preference whether a bettor prefers decimal odds. As you might have guessed, these are demonstrated with a number given to two decimal places. The calculation for decimal odds is as follows: Decimal odds are written as 9.0 (which is the equivalent of 8/1 in fractional odds).

Which Sport are William Hill Best Odds for?

When you see decimal odds displayed, remember that these include your unit stake of one. If you bet £1 at 9.0 and your bet wins, you will get back £9 (initial £1 stake plus £8 winnings). The probability of a 9.0 chance winning is 10% - based on this calculation 1 / (9 + 1) = 0.10 American odds are perhaps the most complicated. A number is given with a plus or minus in front of it. Wagers are odds-on if they have a minus, such as -200 or -500.

How Does Comparing Odds Help Me Find the Best Bonuses?

Anything with a plus, like +500, is odds against. The calculation is based off £100 as the stake. Unlike the presentation of fractional odds, this does not change. A -200 means you need to bet £200 to win £100. If your bet wins your return would be £300 (£200 stake plus £100 winnings). Some promotions will give you money back if your bet loses.

Calculates and displays implied probability for each odds set
Shows the "sharp" bookmaker's line for each market
Identifies arbitrage opportunities across different sportsbooks
Tracks line movement history with graphical charts
Alerts for positive expected value (EV) bets based on model projections

Select this mode to factor in the cashback amount from losing bets. The calculator uses Smarkets colours (green for back, blue for lay) by default. For Betfair colours (blue for back, pink for lay), you can switch in the main website navigation – under the palette icon on non-mobile devices. Use part lays when you have already placed part of your lay bet at the exchange, but more is needed to give an equal profit on every outcome.

Real-time odds updates across major sportsbooks
Highlighting best prices for moneyline, spread, and totals
Filters for specific sports, leagues, and bet types
Side-by-side comparison table layout
Push notifications for odds movements
Direct links to bookmaker sites for placing bets
Option to convert odds between decimal, fractional, and American formats

This instance could arise if you made a mistake with your first lay bet. Enter the part lays you have already placed, and the calculator will give the lay stake required to equalise the profit on all outcomes. Use the slider to weigh your profit towards a win at the bookmaker or the exchange. Doing so can give a higher profit on particular outcomes, which you may want to do to keep things exciting, or if you wish to retain a higher portion of your bonus when completing rollover requirements. My Bonus Rollover Guide has full details.

How to get the most from odds comparison sites

A +300 bet odds comparisons means you have to bet £100 to win £300. If your bet wins the return would be £400 (£100 stake plus £300 winnings). Here is a handy resource for comparing and converting odds between the fractional and decimal betting formats: Odds on simply means an event is more likely to happen than not. It is the opposition of odds against. Any odds-on price carries an implied probability higher than 50%.

What is a Yankee bet?

Any odds-against price has an implied probability below 50%. A bet of exactly evens has an implied probability of 50%, and your winnings will be equal to your stake. In fractional odds, an odds-on wager will see the smaller number on the left than the right. This is flipped for odds-against bets. For instance, 4/6 is an odds-on price with an implied probability of 60%.

2. Instantly Understand the Odds

Flip those odds to 6/4 and the implied probability drops to 40%. When it comes to payouts, an odds-on bet simply means you will win less than you staked. An odds-against wager means you will have larger potential winnings than you stake. So if you placed £4 on England to beat France at 6/4, you would win £10 if the Three Lions were victorious. Learn how to use this calculator to profit from bookmaker promotions in my complete matched betting guide. Click the ‘underlay‘ or ‘overlay‘ headings to set the slider to a position where your bets will result in a reduced profit on either the bookmaker or exchange side and a higher profit on the opposing side. My Reload Offers page contains details of every profitable bookmaker promotion currently available. Filter by ‘Bet X, Get X’, ‘Bet X, Get X if…’, ‘Free Bet’ or ‘Risk-Free Bet’ offer types for offers you can do using this calculator. The calculator at the top of the page does all these calculations for you (and more!). However, if you’re curious or need to know how to calculate lay stakes for matched bets manually, here are the formulas. These formulas give an even profit no matter the outcome of your bets. Lay stake for qualifying betLay stake = (back odds * back stake) / (lay odds – lay commission) Lay stake for free bet if stake not returnedLay stake = (back odds – 1) / (lay odds – lay commission) * free bet value Lay stake for free bet if stake returnedLay stake = (back odds * free bet value) / (lay odds – lay commission) Matched betting is a way of exploiting bookmaker promotions to make a predictable profit from each one. By covering all outcomes of an event, you can meet the requirements for claiming free bets or bonuses while your bets cancel out, resulting in an overall profit or loss close to breakeven. You can then repeat the process to extract about 80% of the free bet amount. For example, you can earn about £8 profit from a £10 free bet. My comprehensive and free Matched Betting Guide will take you through the basic concept with a complete walkthrough of your first bookmaker promotion. You’ll even earn about £15 in the process. Beyond that, my Matched Betting Academy details how to profit from every UK bookmaker’s ‘welcome’ offer, all for free. Designed and tested by matched betting experts, it also provides techniques to make money from extra place offers, 2UPs, price boosts, and other recurring existing customer offers, all logically structured and well-paced. A bet builder is a multi-leg bet on a single game of football.

Join 1,000s of Smarter Bettors

This calculator takes the manual work out of matched betting by calculating the stake you must place at the betting exchange (your lay stake) to get as close to breakeven as possible on your qualifying bets. It also maximises profit when placing your free bets. The amount you need in your exchange account (liquidity) should your back bet win. The distribution of your money between your bookmaker and exchange accounts in the event of each outcome. Your potential profit from a free bet at the current odds.

❓ Why should I use an odds calculator?

How adjusting odds and stakes can impact your overall profit or loss. How you can underlay or overlay – weighing your profit in favour of a particular outcome. How to handle part lays – where you have already placed one or more lay bets but not to the total required to give an even profit between outcomes. This calculator is for making a profit from a range of offer types, the most common being ‘Bet X, Get Y’. I recommend working through my Matched Betting Guide so you can fully understand the matched betting process and its use.

Odds On

Depending on your stage when profiting from a bookmaker promotion, the calculator has a few different modes. Use this mode when placing your initial bets to bet best gambling sites in the world claim your free bet, risk-free bet or bonus. Input the stake and odds from your selected market at the bookmaker (back bet), along with your odds and commission at the exchange (lay bet), and it will show you the amount you need to stake at the exchange (lay stake) to make the minimal loss. Use this mode when turning your free bet into a profit. It works for free bets and bonuses (A bonus is a free bet that needs to be ‘rolled over’ a set number of times before you can withdraw it. For the bet to win, each leg must be successful and is usually made up of three or more separate legs. For example, you could select Man City to beat Man United, Erling Haaland to score, Phil Foden to have a shot on target and Bruno Fernandes to be carded. This is a great way of lengthening the odds of your bet as more is required for the bet builder to win.

3 Brilliant Benefits of Using Our Odds Calculator

Odds – this is the ‘price’ you agree to stake your bet at. Payout – this shows the expected return on your bet, if you are successful Payout – this shows the expected return on your bet, if you are successful A probability is the likelihood of a certain outcome. Betting odds aim to show the probability of a given outcome in a selected sporting event – this can be everything from Joe Root scoring a 50 to Harry Kane scoring two goals in a match. It is possible to calculate the implied probability of an outcome using the betting odds published by a bookmaker. Bookies calculate the chance of an event happening to help them work out their odds.

What Are the Differences Between Online and Offline Odds?

An outcome at short odds will carry a higher implied probability, meaning it is much more likely to happen. Longer odds make an event less likely. In fractional odds, for instance, an event at 5/4 is far more likely than an event at 9/2. There are surprises at all levels of sport. Just because a horse is heavily favoured to win a race, there’s no guarantee it will do so.

Champions League

The same goes for every sport – the challenge with predicting the outcome of sports betting markets is part of the reason online sports gambling has become so popular. Bookmakers will use fractional, decimal, or American odds to display the implied probability of an outcome. Fractional odds are presented with a slash between two numbers. The number on the right is the unit stake. The number on the left represents the potential winnings if you were to place that stake. The oddschecker bet builder tool is simple to use and allows you to select multiple legs for a single game of football and compare the best odds for that particular bet. Currently, all major competition's matches are supported by this oddschecker bet builder tool, such as the Premier League, FA Cup, and Champions League.

OddsGuard - Sports Betting Odds Comparison by OddsGuard