Betfair Exchange: commission, effective odds and arbitrage
- Commission model
- net winnings
- Rate (placeholder)
- 5%
- Even money after commission
- 1.950
- Lay bets
- yes
- Profit on every outcome
- 0.89
- Total stake
- 100.00
- Sum of implied probabilities
- 99.11%
| Leg | Odds used | Effective odds | Stake |
|---|---|---|---|
| Back Outcome 1 | 2.200 | 2.200 | 45.86 |
| Lay Outcome 1 | 1.909 | 1.864 | 54.14backer's stake 49.22 |
| If this wins | Legs that pay | Gross return | Commission | Net profit |
|---|---|---|---|---|
| Outcome 1 | Outcome 1 | 100.89 | 0.00 | 0.89 |
| Not Outcome 1 | Outcome 1 | 103.36 | 2.46 | 0.89 |
Arbitrage: 0.89% return, 0.89 profit on every outcome
Betfair Exchange is a betting exchange that charges 5% commission on net winnings. That changes what every price is worth: even money (2.00) becomes 1.950 after commission, and the win rate you need to break even rises to 51.28%. Everything below is computed at that rate.
Betfair Exchange is the largest betting exchange, with the deepest liquidity in horse racing and soccer. Prices are set by users backing and laying against each other; Betfair takes commission on net winnings per market, and the base rate is reduced by discount tiers that depend on activity.
How Betfair Exchange commission works
Commission on net winnings is charged only when you win, as a percentage of the profit. The
effective odds are 1 + (odds − 1) × (1 − rate). Losing bets pay nothing extra, so the loss side
of the bet is unchanged. This is the model most exchanges use, and it means favourites lose less
value to commission than outsiders do: a 1.20 shot at 5% is barely dented,
while a 10.00 shot loses 5% of a much larger profit.
| Odds | Effective | American | Break-even | Net profit on 100 |
|---|---|---|---|---|
| 1.50 | 1.475 | -211 | 67.80% | 47.50 |
| 1.91 | 1.865 | -116 | 53.63% | 86.45 |
| 2.00 | 1.950 | -105 | 51.28% | 95.00 |
| 2.50 | 2.425 | +142 | 41.24% | 142.50 |
| 3.00 | 2.900 | +190 | 34.48% | 190.00 |
| 5.00 | 4.800 | +380 | 20.83% | 380.00 |
| 10.00 | 9.550 | +855 | 10.47% | 855.00 |
Backing at a bookmaker, laying at Betfair Exchange
The classic use of an exchange is the hedge: back an outcome at a bookmaker, lay the same outcome at Betfair Exchange, and lock in a profit if the two prices are far enough apart. With a back at 2.20 and a lay at 2.10 under 5% commission, staking 100 in total gives 0.89 profit on either result, a 0.89% return (arbitrage: yes). The lay carries a liability of 54.14 against a backer's stake of 49.22.
| Result | Gross return | Commission | Net profit |
|---|---|---|---|
| Outcome wins | 100.89 | 0.00 | 0.89 |
| Outcome loses | 103.36 | 2.46 | 0.89 |
The calculator above is pre-set to this scenario. Change the odds to your own and the stakes update immediately.
Using Betfair Exchange prices to find fair odds
Exchange prices are set by traders rather than by a bookmaker's margin, so after commission they are often close to the fair line. To use them that way, take both sides of a market, remove what little overround remains with the devig calculator pre-set to Betfair Exchange, and compare the result with the bookmaker prices you are offered. A bookmaker price above the fair line is value.
Comparing Betfair Exchange with other venues
The pairs listed at the bottom of this page each open an arbitrage calculator with Betfair Exchange on one leg and another venue on the other, commission applied to both. They are the quickest way to see how much two venues must disagree before a position pays.
Regions and verification
Betfair Exchange lists UK, IE, AU, ES, IT among its markets. Availability, licensing and commission all differ by country; the figures on this page are arithmetic, not a statement about what you can access where you live.
Frequently asked questions
What commission does Betfair Exchange charge?
The placeholder rate on this page is 5% on net winnings, last reviewed 2026-09-09. Rates vary by country, product and discount tier; confirm the figure in your own account.
What are the effective odds of 2.00 at Betfair Exchange?
After 5% commission on net winnings, even money (2.00) is worth 1.950, and the break-even win rate rises to 51.28%.
Can I lay bets at Betfair Exchange?
Yes. Laying at odds L against a backer's stake B risks a liability of B × (L − 1). Commission applies to your profit when the outcome loses.
Is Betfair Exchange a good source of fair odds?
Prices set by traders carry a small overround, so after removing it they are close to a fair line. Remember to account for commission when comparing with a bookmaker price you will actually take.
Does commission apply to every bet?
Most venues charge on the net result of a market rather than on each bet, so offsetting bets in the same market share one commission charge. This site models one bet at a time.