There are two considerations to make when buying replacement bags for your shredder. Usually there is a shredder bag available that matches up to the brand and model of your shredder, ensuring you get the right size to work with your shredder.
But, what if there is a sale on bags for a different shredder model? Or if the store where you want to get your replacement shredder bags is out of the name brand bags for your shredder? In those cases, you can look at two factors to determine if a given shredder bag will fit your shredder: the dimensions and the gallon capacity.
If the dimensions are within a few inches of your shredder's dimensions, it will fit. If the gallon capacity is within 5 gallons of your shredder's capacity, it will fit.
If you have a choice of several sizes, it is better to go for the size closest to - but bigger than - your shredder's recommended bag size.