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Betfair Trading Calculator

Calculate back and lay profit, lay liability, green-up stakes, break-even odds, and commission impact. All calculations update in real time.

Back & Lay Profit
Profit / loss on any back or lay bet
Gross profit if wins£240.00
Commission on profit−£12.00
Net profit if wins£228.00
Total return if wins£328.00
Loss if loses−£100.00
Your liability (max loss)−£240.00
Profit if selection loses£100.00
Commission on profit−£5.00
Net profit if loses£95.00
Loss if selection wins−£240.00
Green Up Calculator
Lock in profit across all outcomes
Green-up lay stake£118.42
Profit if selection wins+£18.00
Profit if selection loses+£18.00
After 5% commission+£17.10
Return on stake (%)17.1%
Lay odds must be lower than back odds for profit. Price must have shortened from your entry.
Lay Liability Calculator
How much you need in your account
Your liability−£200.00
Funds needed in account£200.00
Profit if selection loses£50.00
Liability as % of profit400%
!Liability = Backer's stake × (Odds − 1). This amount is reserved from your balance until the market settles.
!At odds of 5.00: your liability is 4× your profit potential. Laying at high odds requires substantial funds.
Commission Calculator
Impact of Betfair commission on returns
Effective commission rate5.00%
Standard commission−£25.00
Premium Charge−£0.00
Total fees−£25.00
Net profit after all fees£475.00
Break-Even Odds Calculator
What lay odds you need to trade out at breakeven or target profit
Break-even lay odds 4.00
Lay stake at B/E £105.26
Target lay odds 4.00
Ticks of movement needed 0 ticks

How to Use These Calculators

Back & Lay Profit Calculator

Enter your stake, the decimal odds, and the commission rate. The calculator shows your gross profit before commission, the commission deducted, and your net profit after commission. On the Lay tab, it shows your liability (the amount locked in your account while the bet is live) and your profit if the selection loses.

Profit (back) = Stake × (Odds − 1)
Liability (lay) = Backer's stake × (Odds − 1)

Green Up Calculator

This is the core trading calculation. Enter your back stake and the odds at which you backed. Then enter the current odds (which should be lower for a back-to-lay trade). The calculator shows the exact lay stake needed to equalise profit across all outcomes — this is your green-up amount. See our Green Up Explained guide for the full mechanics.

Green-up lay stake = (Back stake × Back odds) / Lay odds
Guaranteed profit = Back stake × ((Back odds / Lay odds) − 1)

Commission Rates to Know

The standard Betfair commission rate is 5%, but many markets have lower Market Base Rates (MBR). Premier League football: 2%. Grand Slam tennis: 3%. Most horse racing: 5%. Your Betfair Discount Rate can reduce these further. Check your account settings for your personal discount. See our commission guide for full details.

Related guides: Bankroll Management · Green Up Explained · Lay Betting Explained · Betfair Review

Ready to Trade

Put the calculator to work. Start trading.

Open a Betfair account and apply these calculations on real markets. Start with £2 stakes — the maths works the same at any size.

Open Betfair Account → Beginner's Guide