Betfair Commission Calculator
Betting exchanges like Betfair don't build a margin into the odds — instead they take a commission on your net winnings in each market. This free calculator shows exactly how much commission you'll pay on a back or lay bet and what you actually keep.
Enter your stake, the decimal odds and your commission rate (Betfair's Market Base Rate varies by market and country — often around 6.5%, and loyalty discounts can lower it). It works for both back and lay bets and shows your gross winnings, the fee, your net profit and — for a back bet — the effective odds once commission is taken.
Effective odds after commission
What 2.50 is really worth once 6.5% commission is taken
2.402
Winnings (gross)
150.00
Commission (6.5%)
−9.75
Net profit if it wins
+140.25
Loss if it loses
−100.00
Serious about your edge?
ProfitBetting tracks every bet's closing line value against Pinnacle automatically — so you know if you're really beating the market, not just guessing.
Frequently asked questions
How is Betfair commission calculated?
Commission is charged on your net winnings in a market, not your stake. On a winning back bet at odds O with stake S, the winnings are S×(O−1); the fee is that × your commission rate. A £100 back at 2.50 wins £150; at 5% commission the fee is £7.50, so you keep £142.50.
Do I pay commission on losing bets?
No. Commission is only ever charged on net winnings. Losing bets pay nothing extra — for a back bet you simply lose your stake, and for a lay bet you lose the liability.
What commission rate should I use?
Betfair's Market Base Rate varies by market and country — commonly around 6.5%, though it can be 2–7%, and loyalty discounts (Betfair Points) can reduce your effective rate. Other exchanges are cheaper — Smarkets and Matchbook are around 2%. Use the rate that applies to your account.
How does commission affect lay bets?
When you lay a selection and it loses (i.e. your bet wins), you keep the backer's stake minus commission; when it wins you pay the full liability with no fee. So a lay is only reduced by commission on the winning side.
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<p style="font:13px/1.4 system-ui,sans-serif;margin:8px 0 0">Free <a href="https://profitbetting.io/tools/betfair-commission-calculator">Betfair Commission Calculator</a> by ProfitBetting</p>