An accumulator is a bet of four or more different selections that are combined into one bet. All the selections need to be correct for the bet to win.
Accumulators - often referred to as accas - are popular because they offer the opportunity to win big from a small stake. They combine all of the odds from each selection to create the total odds. An accumulator offers higher odds than a single bet because of the greater risk, as multiple outcomes must be correct for the bet to win.
You can create an accumulator for most sports, including horse racing, darts and football. However, you cannot create an accumulator using multiple selections from the same match, as this is a same game multiple.
Accumulators must consist of at least four selections. A two selection bet is referred to as a double and three selections is called a treble.
Types of accumulators
Accumulators can consist of anything between four and 20 selections. An accumulator with four selections is called a four-fold acca, an accumulator with five selections is a five-fold acca and so on.
As the success of an accumulator hinges on multiple outcomes, the risk can be reduced through an each-way accumulator. This is a type of acca predominantly used in horse racing, whereby the stake is doubled and the bettor can still receive a return if their chosen horses fail to win but still manage to place.
How are accumulators calculated?
Accumulators are calculated by multiplying the odds of each selection together to give you the total odds. The price increases everytime another selection is added to the accumulator.
How are accumulators calculated using decimal odds?
An accumulator with decimal odds is calculated by multiplying the odds of each selection together. For example, a five-fold acca using decimal odds would be calculated as follows:
Manchester United vs Manchester City - Manchester United to win at odds of 1.70
Tottenham vs Arsenal - both teams to score at odds of 1.86
Liverpool vs Everton - over 2.5 goals at odds of 2.15
Chelsea vs West Ham - Chelsea to win at odds of 1.98
Wolves vs Leicester - Leicester to win at odds of 2.19
1.70 * 1.86 * 2.15 * 1.98 * 2.19 = 29.48
Therefore a £10 stake would see a payout of £294.80
How are accumulators calculated using fractional odds?
An accumulator using fractional odds would be calculated by converting the fractions into decimal odds and then multiplying them all together, as demonstrated above.
Fractional odds are converted into decimal odds using the following formula:
Numerator (the first number) / denominator (the second number) + 1
For example, a four-fold acca with fractional odds would be calculated as follows:
Barcelona vs Real Madrid - under 2.5 goals at odds of 3/4
Atletico Madrid vs Valencia - Atletico Madrid to win at odds of 4/7
Villarreal vs Real Sociedad - both teams to score at odds of 5/9
Sevilla vs Athletic Club - Sevilla to win at odds of 1/1
3 / 4 + 1 = 1.75
4 / 7 + 1 = 1.57
5 / 9 + 1 = 1.56
1 / 1 + 1 = 2.00
1.75 * 1.57 * 1.56 * 2.00 = 8.57
Therefore a £10 stake would see a payout of £85.70.
How are accumulators calculated using American odds?
Accumulators with American odds are calculated by coverting the odds into decimal odds, and then multiplying them all together, as demonstrated above.
For positive odds, the formula for converting American odds into decimal odds is:
Odds / 100 + 1
For negative odds, the formula for converting American odds into decimal odds is:
100 / Odds + 1
For example, a four-fold acca using American odds would be calculated as follows:
Inter Milan vs AC Milan - Inter to win at odds of -250
Juventus vs Turin - Juventus to win at odds of -160
Atalanta vs Roma - over 2.5 goals at odds of +150
Napoli vs Lazio - both teams to score at odds of -170
100 / 250 + 1 = 1.40
100 / 160 + 1 = 1.63
150 / 100 + 1 = 2.50
100 / 170 + 1 = 1.59
1.40 * 1.63 * 2.50 * 1.59 = 9.07
Therefore a £10 stake would see a payout of £90.70
How to use accumulators to improve your betting
Accumulators are a great way to see a big return from a small stake. However, increasing the number of selections always increases the risk of a bet and makes it more difficult to win an accumulator.
Make sure you research each selection first as the chance of losing is so high, and use implied probability for each selection to ensure that the bets represent value. Each-way accumulators can be helpful, particularly if you are not backing a favourite.