UK · Prediction markets · Free tool
Betting exchange commission calculator
Enter the odds, your stake and the exchange’s commission to see what a back or lay bet really pays, the odds after commission, and whether the exchange beats a bookmaker’s price.
Exchange commission calculator
Net profit if it winsNet profit if it loses
£107.80
If it wins, after £2.20 commission on £110.00 of winnings: £207.80 back in total.
- Commission
- £2.20
- Odds after commission
- 2.08 (83/77)
- Exchange odds needed to beat the bookmaker
- 2.07 (15/14)
- Liability (lay bets)
- —
The exchange pays £2.80 more if it wins
Exchanges charge commission on your net winnings in a market, so a losing bet costs nothing extra. Odds accept decimal (2.10), fractional (11/10) or American (+110) formats.
Commission at UK exchanges
The standard commission each exchange publishes, and what a winning £100 back bet at odds of 3.00 (2/1) returns after it.
| Exchange | Commission | What applies | £100 at 2/1 returns |
|---|---|---|---|
| Smarkets | 2.0% | Standard tier: 2% on net profits per market. A 1% Pro tier applies above 1,500 bets or £1m staked in a month, and a 3% Select tier to the few customers with more than £25,000 of net profit over 12 months. | £296.00 |
| Betfair Exchange | 2.0% | Basic package of My Betfair Rewards: 2% of net winnings per market, the rate in Betfair’s own worked example; other packages aren’t published. Accounts with more than £25,000 of gross profit over 52 active weeks can also pay an Expert Fee. | £296.00 |
| A bookmaker at the same odds | — | No commission: the bookmaker’s margin is built into its odds instead. | £300.00 |
How the calculator works
On a betting exchange you bet against other users. You can back an outcome, betting that it happens, or lay it, betting that it doesn’t, by accepting another user’s back bet. The exchange doesn’t build a margin into the odds; it takes a commission on your net winnings in each market instead.
For a back bet, your net profit is stake × (odds − 1) × (1 − commission), so a 2% commission turns odds of 3.00 into an effective 2.96. For a lay bet, you risk the liability, stake × (odds − 1), to win the backer’s stake, less commission. Enter a bookmaker’s odds on the same outcome to see which pays more, and the exchange odds you’d need to beat the bookmaker after commission. Bookmaker margins can be worked out with our bookmaker margin calculator.
Frequently asked questions
How is betting exchange commission calculated?
As a percentage of your net winnings in a market: if a £100 back bet at 3.00 wins, the £200 profit at 2% commission costs £4, leaving £196. If you lose the market overall, you pay no commission on it.
Is an exchange cheaper than a bookmaker?
Often, because the exchange takes commission instead of building a margin into its odds, but not always: compare the exchange price after commission with the bookmaker’s odds. The calculator shows the exchange odds you need to beat a bookmaker.
What is a lay bet?
A bet that an outcome won’t happen. You accept another user’s back bet: if the outcome doesn’t happen you win their stake, less commission; if it does, you pay out their winnings, your liability.
Do exchanges charge extra fees?
Some charge their most profitable customers more. Smarkets applies a 3% Select tier to customers with more than £25,000 of net profit over 12 months, and Betfair can charge an Expert Fee to accounts with more than £25,000 of gross profit over 52 active weeks.
Keep reading
Sources
We verify facts against primary sources (regulators, court records, operators’ own terms) wherever possible.
- Smarkets commission FAQ — Smarkets , updated 2025-02-17
- Betfair charges — Betfair , Internet Archive capture of 2025-10-11