Odds Calculator

Work out what a bet pays before you place it, then check the payout is right after it settles. This calculator handles singles, each-way bets, doubles, trebles and accumulators, along with full cover bets like Trixies, Patents, Yankees and the Lucky 15, 31 and 63. It reads fractional odds the way Irish bookmakers write them and decimal odds the way most apps display them. Stakes are in euro, each-way terms default to Irish place terms, and you can apply the settlement rules that change a return after the event: Rule 4 deductions, dead heats, void legs and free bet stakes.

What a bet calculator actually does

It converts between odds formats, so you can compare a shop price of 7/2 with the 4.50 showing on an app. It multiplies your stake across your selections, which matters because the odds in a multiple multiply together instead of adding up. And it applies the rules that decide the final figure once the race or the match is over.

For a single bet you can do the sums in your head. For a €1 Lucky 15 with four winners and a bonus on top, or a five-fold where one leg turned into a non-runner, you cannot. That is where punters either talk themselves into a payout they were never owed or fail to spot that they have been shorted.

One thing to get straight first, because it is the most common misreading of any calculator output. A €10 bet at 7/2 returns €45, and your profit is €35. The extra €10 is your own stake coming back. Slips and calculators usually show the return, so when you want to know whether you are up or down for the day, look at the profit.

How to use the bet calculator

1. Pick the bet type. Single, each-way, double, treble, four-fold or bigger, or one of the full cover bets. The number of odds fields changes to match.
2. Enter your stake. This is the field people get wrong. On multiple bets the amount you type is the stake per line rather than the total, so a Lucky 15 runs to fifteen lines and €1 a line costs you €15. The total outlay is shown underneath.
3. Enter your odds. Type them however you have them. 7/2, 11/4 and evens all work, and so does 4.50. You can mix formats inside the same multiple.
4. Set your each-way terms if you are backing a horse each-way. Choose the number of places and the fraction of the odds paid. The calculator picks standard Irish terms from the field size, and you can override them for a festival card with extra places.
5. Add any adjustments. Tick a Rule 4 deduction, a dead heat, a void selection or a bonus if one applies to your bet.
6. Read the output. Your total stake, total return and profit are shown as separate figures. Open the detail on a multiple to see it line by line, which is how you find out which leg cost you.

When your figure and the bookmaker's figure disagree, the cause is nearly always one of the adjustments in step five rather than the arithmetic.

Understanding odds: fractional, decimal and probability

Irish racing prices in fractions. Walk into a shop in Ballsbridge or stand at the rails at Leopardstown and you will see 5/2 and 11/4, not 3.50 and 3.75. Most betting apps default to decimal because it is easier to multiply and easier to fit on a phone screen. Both describe the same bet.

Fractional odds tell you your profit relative to your stake, so 5/2 means five units of profit for every two you put on. Decimal odds tell you your total return for each unit, so 3.50 means €3.50 comes back for every €1, your own euro included.

The third column is the one worth learning. Divide 1 by the decimal odds and you have the implied probability, which is the bookmaker's opinion of the chance written as a percentage. A horse at 7/2 is priced as a 22.2% shot. If you have watched it work and you think it is closer to one in three, the price is worth taking. If you have it at 15%, it is not. Anything shorter than evens is odds-on, meaning you stake more than you stand to win, and anything longer is odds-against.

Add up the implied probabilities of every outcome in a market and the total comes to more than 100%. That surplus is the bookmaker's margin, which is why the same bet is worth more with one firm than another.

Take Ireland against Scotland in the Six Nations. Ireland at 1/5 is 83.3%, Scotland at 9/2 is 18.2%, the draw at 25/1 is 3.8%. Together that is 105.4%, so the margin built into the market is 5.4%. A book priced at 103% is a better one to bet into than a book at 108%, whichever side you fancy.

Working out singles and each-way bets

A single is straightforward. Put €20 on a novice hurdler at 11/4 at Punchestown and your profit is €20 multiplied by 2.75, which is €55, for a return of €75.

Each-way is the bet Irish punters place most often and calculate wrong most often. It is two bets of the same size, one that the horse wins and one that it finishes in the places, so €5 each-way costs €10. The place half is settled at a fraction of the win odds, usually a quarter or a fifth depending on the race.

Here is €5 each-way on a 12/1 chance in a 16-runner handicap at Galway, with terms of a quarter the odds and four places.

The place odds of 3/1 are just 12/1 divided by four. Look at that last row, because it is the row people forget about. Your horse ran a blinder, finished third, and you are €10 up on a €10 outlay. Each-way is insurance rather than a route to a big win.

Irish each-way place terms

Festival cards are the exception. At Galway, Punchestown, Fairyhouse, Cheltenham and Aintree, bookmakers often pay an extra place or two on the big handicaps. Set the number of places by hand and you can see what those offers are actually worth. An extra place on a 12/1 shot is real money.

Multiples, accumulators and full cover bets

In a multiple, each winning leg's return rolls onto the next one. Working in decimal odds makes it easy: multiply them all together, then multiply by your stake.

Here is a Saturday four-fold across the League of Ireland and the GAA.

1.80 x 2.50 x 2.00 x 3.50 = 31.50

A €10 stake returns €315, a profit of €305. Notice what the multiplication does. Four fairly ordinary prices, nothing longer than 5/2, combine into better than 30/1. That is the appeal of an accumulator, and also the reason accas lose far more often than they look like they should.

Full cover bets

Full cover bets split your selections into every possible combination, so you can still collect when one of them lets you down. You pay for that in stake, because every line costs.

Take a Lucky 15 in full. Four selections at 2/1, 3/1, 5/2 and evens, at €1 a line, so €15 out of your pocket. All four win.

That is a profit of €281.45 on a €15 stake.

The two bonuses are the part no manual calculation gets right. Most bookmakers add around 10% when all four selections win, and pay double the odds on the single if exactly one wins. So if only the 3/1 obliges, that line settles at 6/1 and returns €7 instead of €4. You are still €8 down on the bet, which is worth knowing before you place it rather than after.

Bonus terms vary between firms, and some apply the percentage to winnings instead of total returns. Set the bonus fields to match your bookmaker and the calculator will follow those rules.

The rules that change your payout

These adjustments are what usually make a settled bet look wrong.

Rule 4 deductions

If a horse is withdrawn before a race and there is no time to re-form the market, every runner left in has an easier task than its price suggested. Bookmakers correct for that by taking a set amount out of winnings, on a sliding scale based on the price of the horse that came out.

Say you have €20 at 5/1 and a 2/1 shot is withdrawn. Your profit would have been €100. A 2/1 withdrawal carries a deduction of 30c in the euro, so €30 comes off and you are left with a profit of €70 and a return of €90.

The deduction only ever comes off winnings, never your stake. The shorter the withdrawn horse, the bigger the hit, and a withdrawn odds-on favourite can take half your profit. Anything longer than 14/1 usually triggers no deduction at all.

Dead heats

When two horses cannot be separated on the line, your stake is split by the number of runners tying. Half is settled as a winner at full odds and half loses. So €10 at 4/1 in a two-way dead heat gives you €5 at 4/1, a return of €25 rather than €50.

Void legs and non-runners

If a selection in a multiple is a non-runner, or the event is abandoned, that leg is voided at odds of 1.00 and the bet drops a tier. A five-fold becomes a four-fold and your stake stays where it is.

Go back to the four-fold above and suppose Kerry's match is called off. Divide the combined 31.50 by that leg's 3.50, which leaves 9.00, so €10 returns €90 if the other three win.

Free bets where the stake is not returned

Most free bets pay you the winnings only. A €20 free bet at 3/1 pays €60, not €80. The missing €20 is the free stake, which was never yours to get back. Set the calculator to exclude the stake and it will price the offer honestly, which is useful when you are weighing a €20 free bet against a smaller cash bonus.

Best Odds Guaranteed

If you take an early price and the horse starts at bigger odds, Best Odds Guaranteed pays you the better of the two. Backed at 5/1, went off at 13/2: on €20 that is €130 profit instead of €100, so the concession was worth €30 on one bet. Run both prices through the calculator across a few bets and you will see why BOG is worth more to a racing punter than most sign-up offers.

Tax on betting winnings in Ireland

Irish punters pay no tax on betting winnings. Winnings from betting are not chargeable gains under Section 613(2) of the Taxes Consolidation Act 1997, so there is nothing to declare and nothing to pay, whether you win €50 or €50,000.

The tax that does exist sits with the operator. Licensed bookmakers pay a 2% betting duty on stakes taken from Irish customers, a rate that has been in place since 2019, and betting exchanges pay 25% on the commission they earn. Revenue collects both. The duty is charged on turnover rather than profit and it is the bookmaker's liability, so it never appears on your account or your slip. Where it reaches you at all, it reaches you the way any business cost does, through slightly tighter odds. Licensing itself now sits with the Gambling Regulatory Authority of Ireland under the Gambling Regulation Act 2024.

So a return the calculator shows as €90 should arrive as €90. If it does not, look for a settlement rule rather than a tax.

Using the calculator to find value

Once you are comfortable working out returns, the same tool answers a more useful question: is this bet worth making?

Start with expected value, which sets your own view of a chance against the price on offer. Back €10 at 3/1 on something you rate a 30% shot and the sum runs (0.30 x €30) minus (0.70 x €10), which comes to plus €2. A bet with a positive figure is worth repeating even though it loses most of the time. A negative one is not, however well it happens to go on the day.

Cash out offers are worth checking before you accept one. That €10 four-fold returning €315 is three legs down with Kerry to come at 3.50. Divide €315 by 3.50 and the position is worth roughly €90, so an offer of €70 is the bookmaker taking a healthy cut for the convenience.

Dutching is the last one. If you fancy two runners in the same race, you can stake so that either result pays you the same. Split €50 across a 2/1 chance and a 7/2 chance by putting €30 on the first and €20 on the second, and both return €90 for a €40 profit whichever one obliges. The split follows the implied probabilities, which is a fiddly sum by hand and instant here.

Before you use it

The calculator tells you what a bet pays. It cannot tell you whether it will win, and no calculator, system or staking plan changes the fact that the odds carry a margin in the bookmaker's favour. Use it to understand the bets you already place, to check you have been paid correctly, and to see plainly what a long accumulator is really worth.

If betting has stopped being enjoyable, free and confidential support is available from Gambling Care (gamblingcare.ie) and Problem Gambling Ireland (problemgambling.ie). Every licensed bookmaker offers deposit limits and self-exclusion. Betting is for over-18s only.