How to Use a Matched Betting Calculator
A matched betting calculator removes all the maths — it tells you exactly how much to lay, what your qualifying loss will be, and how much profit you'll lock in from each free bet.
What the Matched Betting Calculator Does
The back and lay odds are never identical, and exchange commission differs per platform. A calculator handles all these variables instantly — no spreadsheet required.
Calculates the lay stake
Tells you exactly how much to place on the exchange to perfectly offset your bookmaker bet, ensuring you're covered regardless of the result.
Shows your qualifying loss
Calculates the small, predictable cost of unlocking a free bet, caused by the slight difference between back and lay odds.
Tells you your free bet profit
Provides the final, guaranteed cash amount you'll extract from a free bet after all outcomes are covered.
Our Matched Betting Calculator handles both qualifying bets and SNR/SR free bets in one place. You enter the numbers — it handles the rest.
What to Enter Into the Calculator
Bookmaker Side
This is where you enter the details from the bookies' site. It calculates your initial stake and the potential return if your back bet wins.
Exchange Side
This is where you enter the lay odds and commission. It calculates how much you need to "sell" on the exchange to cover your bet.
📥 Back Inputs
Back stake — how much you're betting (e.g. £10).
Back odds — the decimal odds at the bookmaker (e.g. 3.00).
Bet type — Normal for qualifying bets, or Free Bet (SNR/SR).
📤 Lay Inputs
Lay odds — the decimal odds on the exchange (e.g. 3.10).
Commission — the exchange's cut of winnings (e.g. 2% for Betfair).
Bookmaker sites often show fractional odds (e.g. 2/1). Convert to decimal by dividing and adding 1 — so 2/1 = 3.00. Our calculator accepts decimal odds only.
Qualifying Bet Walkthrough
You're completing a Bet £10, Get £30 offer. You find a match with 3.00 back odds at Bet365 and 3.10 lay odds on Betfair (2% commission).
This is a qualifying bet — you're using your own money. Select "Normal" (not Free Bet) from the dropdown.
Back stake: £10. Back odds: 3.00. Lay odds: 3.10. Commission: 2%. Hit calculate.
The calculator shows: Lay stake ≈ £9.90. Qualifying loss ≈ –£0.98. This is what it costs to unlock your free bet.
⚠️ Expected qualifying loss: ~£1Back £10 at Bet365 and lay £9.90 on Betfair. The event result doesn't matter — you'll lose around £1 either way, and unlock your £30 free bet.
Free Bet Walkthrough (SNR)
Now you have your £30 free bet. Set the bet type to Free Bet – Stake Not Returned (SNR). This ensures the calculator accounts for the stake being removed from winnings.
This tells the calculator that the stake won't be returned with your winnings, which affects the lay calculation.
Higher odds = more profit extracted from the free bet. Aim for back odds between 4.00–8.00 for maximum SNR efficiency.
With a £30 SNR free bet at odds of 5.00 and a tight lay match, your calculator will show a profit of approximately £23–£24.
✅ Expected profit: ~£23 from a £30 free betA £30 SNR free bet typically returns £22–£25 in profit after the lay. This is because you're only extracting the winnings portion of the free bet — since the stake isn't returned to you if the back wins.
Tips to Get Accurate Results
Match odds simultaneously
Check both the bookmaker and exchange tabs at the same time and place both bets within seconds. Odds can shift between the two placements.
Check exchange liquidity
If less money is available at your lay odds than your required lay stake, split the match or find a different event with better liquidity.
Use the correct commission rate
Betfair's standard rate is 2%, but yours may be lower if you've earned a loyalty discount. An incorrect commission will give you a wrong lay stake.
Don't round the lay stake
Use the exact figure the calculator gives you. Rounding even slightly costs real money compounded across every single bet you place.
Use our Matched Betting Calculator — it supports both Normal and Free Bet (SNR/SR) modes with live commission adjustment.
Common Questions
The wider the gap between back and lay odds, the larger your qualifying loss. Aim for events where the lay odds are no more than 0.10–0.15 above the back odds. Use an odds matching tool to find the tightest matches.
No — standard matched betting calculators are for single events. Accumulator matched betting (using acca insurance offers) uses more advanced techniques and a different calculation approach.
SNR (Stake Not Returned) means if your free bet wins, you keep the profit but not the original stake. SR (Stake Returned) means you keep both. SR free bets are worth more — you extract ~90–95% of their value compared to ~75–85% for SNR. Always select the correct type in the calculator. Learn more in our Free Bets guide.
How do I know if I'm actually making a profit?
With dozens of bets across different bookmakers, it's easy to lose track. Let's look at the essential systems for tracking your bankroll and measuring your success.
Next: Record Keeping & Tracking →