Matched Betting Calculator
Find the exact lay stake to match a back bet at the bookmaker with an equal-and-opposite position at a betting exchange, locking in a known result regardless of the outcome. Works for both real-money qualifier bets and free-bet (SNR) conversions.
Bet type
%
Small loss to unlock the free bet — a one-off cost
- 1
Commission fraction
5 ÷ 100 = 0.05 - 2
Effective lay denominator
3.1 − 0.05 = 3.05 - 3
Lay stake
10 × 3 ÷ 3.05 = 9.84Sized so one outcome always wins the same as the other loses - 4
Qualifying loss
10 × (3 − 1) − 9.84 × (3.1 − 1) = -0.66
How does this calculator work?
Matched betting pairs a back bet at a bookmaker with a lay at an exchange to guarantee the same result either way. Qualifier lay stake = Back stake × Back odds ÷ (Lay odds − commission). Free-bet (SNR) lay stake = Back stake × (Back odds − 1) ÷ (Lay odds − commission), yielding a profit of Lay stake × (1 − commission).
Formula
How this is calculated
Matched betting uses two bets — a back bet at a bookmaker and a lay bet at an exchange — so that one side always wins. The lay stake is calculated to make the back-wins profit equal to the lay-wins profit, eliminating risk.
For a qualifier (real money): Lay stake = Back stake × Back odds ÷ (Lay odds − commission). Because exchange odds are usually fractionally higher than bookmaker odds, a small qualifying loss is normal — you pay a spread to unlock a free bet. For a free-bet (SNR) match, the stake is not returned on a winning back bet, so: Lay stake = Back stake × (Back odds − 1) ÷ (Lay odds − commission), and the guaranteed profit is Lay stake × (1 − commission).
All odds must be in decimal format (e.g. 3.00, not 2/1). The calculator does not account for bookmaker restrictions, account limitations, or any jurisdiction-specific gambling tax — check local regulations before matched betting.
Frequently asked questions
Exchange lay odds are almost always slightly above bookmaker back odds, so you pay a spread. Choosing markets where the two odds are very close (e.g. within 0.05) minimises this loss and maximises the overall profit after the free bet.
SNR stands for "stake not returned". With a standard free bet you receive only the winnings (stake × (odds − 1)), not the original stake back. The free-bet lay formula accounts for this so that the profit is the same whether the selection wins or loses.
Betfair charges a standard 5% commission on winning lay bets. Smarkets and Matchbook typically charge 2–3%. Enter your actual account rate — some high-volume accounts get reduced commission.
Also known as
TG we-Calculate Editorial Team. (2026). Matched Betting Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/matched-betting-calculator
TG we-Calculate Editorial Team. "Matched Betting Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/matched-betting-calculator.
TG we-Calculate Editorial Team, "Matched Betting Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/matched-betting-calculator
@misc{wecalculate_matched_betting_calculator, title = {Matched Betting Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/matched-betting-calculator}}, year = {2026}, note = {TG we-Calculate} }
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