It is hard to put exact odds on slots machines. With such a variety of slots and game bonuses available you can see the odds can vary a great deal. When looking for odds for slots you will want to look at the payback percentage. The closer to 100% the better the chance you have at winning. At land-based casinos some slots pay percentages greater than 100%. Casinos feel that if other people see a person winning constantly on a machine it will excite them making them want to keep playing themselves.
Online slots pay better than land-based casinos. Land-based casinos slot payback is around 94%. The same slots online pay about 98%. Some online casinos have machines that top the 100% mark to encourage customers to stick with them and not the hundreds of other online casinos out there.