Betting tools
Rule 4 Deduction Calculator
Enter the original odds and the Rule 4 deduction to see the equivalent odds after the deduction.
Calculate effective odds
Enter the quoted odds and supplied deduction.
Decimal, Fractional and signed American odds are detected automatically.
10% is the same as a 10p deduction in the pound.
Enter any currency amount. Results use the same units.
Understanding the calculation
What does Rule 4 deduct?
It reduces potential winnings, or profit, by the percentage you enter.
Why is the stake not deducted?
A winning bet returns its stake separately from profit, so the deduction applies only to winnings.
What do effective odds mean?
They express the reduced profit as equivalent odds for comparison. They do not mean the bookmaker changed the quoted starting price.
How is adjusted return calculated?
The calculator adds the returned stake to profit after the supplied deduction.
Worked example: 11/2 with 10% deducted
Odds of 11/2 have a 5.50 profit multiplier. Keeping 90% gives 4.95 profit, equivalent to 99/20, 5.95 or +495. A stake of 10 returns 59.50 after a 5.50 deduction.
Learn more about Rule 4
Bookmaker rules determine whether a deduction applies and which percentage is used. SlipLogic applies only the value you enter.