Home » bet calculator » rule 4
Ian Bruce

The free Rule 4 calculator on this page will let you work out bet returns even when they involve Rule 4 deductions. No bettor likes Rule 4, but it’s important for fair betting markets in horse racing and other sports. Use this calculator, and whether you’re betting to win or each way, it will tell you exactly how much you’ll get back from the bookie.

Single & Each Way

Total Stake

Total Return

Total Profit

What is a Rule 4 Deduction?

Before we discuss how to use our Rule 4 bet calculator, we should first explain what a Rule 4 deduction is. Basically, it’s something that adjusts payouts on winning bets in events where one or more competitors are withdrawn. Horse racing Rule 4 deductions are most common, but the rule can also apply to other sports. For that reason, someone who likes to bet on greyhound racing or golf can be just as affected as a horse racing fan.

When the oddsmakers at online betting sites set their prices for competitors in an event, they do so based on the assumption that all of those competitors will participate. If bets are made and then one or more competitors withdraw, it can give the remaining competitors a better chance of winning. That means the odds should be shorter than the ones that were taken by previous bettors.

That’s where Rule 4 comes in. If a competitor withdraws at odds of 14/1 or less, payouts on previously made bets will be reduced to reflect that withdrawal. The shorter the odds of the withdrawn competitor, the larger the Rule 4 deduction will be. We will provide you with a Rule 4 deductions table later that shows the exact correlation between odds and deductions.

Rule 4 is important to keep things fair for all concerned and the Gambling Commission works hard to ensure bookmakers use it properly. But because it leads to lower payouts, few bettors would claim to like it. The fact that it also complicates calculating returns on bets makes it even less popular. Fortunately, for our free bet calculator Rule 4 deductions don’t pose any problem at all.

How to Use Our Bet Calculator with Rule 4

This Rule 4 deductions calculator has been designed to be as easy to use as possible. Here’s how to use it to figure out your returns for any bet you care to make.

  1. Choose Bet Type

    With our Rule 4 calculator UK bettors can work out singles, doubles, trebles, accumulators and more. Start by choosing the type of bet that you want to calculate by tapping the corresponding button at the top of the app. If you want to perform a calculation for an each way bet, go to the Each Way selection area and say Yes.
  2. Select the Odds Format

    Now go to the Odds Format area and select how you would like to enter the odds for your bet. You can choose from fractional, decimal or American odds.
  3. Choose the Place Term

    For an each-way bet, our Rule 4 calculator will need to know what fraction of the odds your bookmaker will pay you for a place. You should select the appropriate fraction – commonly 1/4 or 1/5 – by using the Place Term pulldown menu.
  4. Input Your Stake

    The next bit of information the Rule 4 deduction calculator needs is your stake. Input the amount of money that you have bet in the Unit Stake area. For example, if you are betting on horse racing and you have bet £10 each way, you would enter 10 as the unit stake and the overall outlay of £20 would be shown as the Total Stake at the foot of the app.
  5. Input the Odds

    Next, you need to input the betting odds for your bet. Simply enter the odds in the format you previously selected for each leg of your bet.
  6. Choose the Result

    This is where you give our Rule 4 calculator the result of your bet. You can choose from Won, Placed, Dead Heat, Lost or Void. This is also where you should provide the all-important Rule 4 information by selecting the size of the deduction from the Rule 4 menu.
  7. Calculate the Payout

    Finally, tap the Calculate button and the Rule 4 calculator will crunch the numbers you’ve given it to determine your Total Return and Total Profit.

Rule 4 Ready Reckoner

We said earlier that the shorter the odds of a withdrawn competitor, the larger the Rule 4 deduction will be on bets already made. In the old days, it was common for people to use a horse racing ready reckoner to see how much a deduction would be. So, to give a nod to tradition and at the same time show you the relationship between odds and deductions, allow us to present our own Rule 4 chart of deductions.

Fractional Odds of Withdrawn Horse Rule 4 Deduction per £1
14/1 or longer No Deduction
10/1 to 14/1 5p
6/1 to 9/1 10p
9/2 to 11/2 15p
16/5 to 4/1 20p
12/5 to 3/1 25p
9/5 to 9/4 30p
8/5 to 7/4 35p
5/4 to 6/4 40p
1/1 to 6/5 45p
20/21 to 5/6 50p
4/5 to 4/6 55p
8/13 to 4/7 60p
8/15 to 4/9 65p
2/5 to 1/3 70p
3/10 to 2/7 75p
1/4 to 1/5 80p
2/11 to 2/17 85p
1/9 or shorter 90p

Additional Free Bet Calculators

When you have used this Rule 4 calculator you might also want to consider our other apps. We have an accumulator bet calculator, an each-way bet calculator, a dedicated horse bet calculator, a Lucky 15 bet calculator and more. Take a look at our Free Bet Calculator page for more details.


What is a Rule 4 deduction?

What is Rule 4 in horse racing?

How much is a Rule 4 deduction?

What is the Rule 4 scale?

How do you calculate Rule 4?

Ian Bruce

Ian Bruce joined Safest Betting Sites in 2024 as Senior Sports Editor to oversee the quality and usefulness of its gambling content. He originally developed an interest in betting after landing a winning Yankee on his first attempt. He then spent years figuring out how to replicate that success. Along the way, he became one of the UK’s leading writers on the topic of betting and gaming. Ian’s career has now spanned more than three decades, and his enthusiasm for systematic and responsible betting hasn’t waned one bit. However, his preferred approach to winning these days is Dutching, for the simple reason that “It’s a lot easier than landing Yankees.”