New to matched betting? Learn how to use this calculator to profit from bookmaker promotions in my complete matched betting guide.

Select bet type

Qualifying Bet - Use when placing a bet to qualify for a free bet or bonus.

Free Bet - Use when converting a free bet or bonus into cash.

Money Back if Bet Loses - Use when losing stakes are refunded.

Back Bet (Bookie)

Advanced

Back stake

Stake returned

Cashback

Back odds (decimal)

Back commission

%

Lay Bet (Betting Exchange)

Lay odds (decimal)

Lay commission

%

+ Add part lay

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Underlay

Standard

Overlay

Min £

Minimum

Max £

Maximum

Lay stake required: £

Bookie

Exchange

Cashback

Total

If back (bookie) bet wins

£

£

£

= £

If lay (exchange) bet wins

£

£

£

= £

Total profit: £

Optimal Underlay

Lay stake required: £
Total exchange Exchange liability: £

If back (bookie) bet wins: £
If lay (exchange) bet wins: £

Optimal Overlay

Lay stake required: £
Total exchange Exchange liability: £

If back (bookie) bet wins: £
If lay (exchange) bet wins: £

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What is this calculator for?

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. It also shows:

• 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.
• 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.

How to use this calculator

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.

Depending on your stage when profiting from a bookmaker promotion, the calculator has a few different modes.

Qualifying bet

Use this mode when placing your initial bets to 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.

Free bet

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

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.

Money back if bet loses

Some promotions will give you money back if your bet loses. E.g. ‘Bet £10 and get £5 back if your bet loses’. Select this mode to factor in the cashback amount from losing bets.

Back and lay colours

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.

Advanced settings

Part lays

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. 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.

Under and overlaying

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.

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.

Where can I find promotions to use with this calculator?

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.

Manual calculations

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 bet
Lay stake = (back odds * back stake) / (lay odds – lay commission)

Lay stake for free bet if stake not returned
Lay stake = (back odds – 1) / (lay odds – lay commission) * free bet value

Lay stake for free bet if stake returned
Lay stake = (back odds * free bet value) / (lay odds – lay commission)

What is matched betting?

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.

Learn Matched Betting
the free, easy way

Make £600+ from bookmaker welcome offers.