Use our Accumulator calculator to work out how much you can win or have won from your Accumulator bet. Our free betting calculator is Easy to Use and mobile friendly. The Accumulator is the simplest form of multiple bet that exists. You can combine any amount of selections for an accumulator bet and the unit stake that you choose is all that you pay. There is just one betting line in an Accumulator but all your chosen selections must win in order for there to be a return.