Comparison XD Design Bobby Hero XL 21.5 L vs XD Design Bobby Hero Regular 18 L

The working volume of a backpack determines the maximum amount of cargo that can be carried in it. Note that not all manufacturers indicate this parameter in the same way: in one case it can only be the volume of the main compartment, in the other — the total capacity, taking into account all compartments and pockets. If the exact value is important for you, you should separately specify this parameter for each model of interest.

The optimal volume of a backpack is directly related to its intended purpose and features of use. For example, for an urban model designed for documents and textbooks, most often 10 liters is enough, and for trips lasting several days, about 60-70 liters, or even more, may be needed. In general, when choosing the optimal volume for a hiking backpack, it is best to turn to reference literature, or for advice from experienced “hikers”.

Note that the volume of the backpack can often be adjusted. One of the options is side ties (see "Design") to change the thickness. And in some versions, it may also be possible to change the volume due to a special folding insert made of fabric — if necessary, it can be expanded and the height of the backpack can be increased. The names of such models often contain two numbers, for example 35:45 — they indicate the volume in the folded and unfolded form, respectively. In our catalog for these options, the maximum volume is indicated, in the unfolded position.

The maximum diagonal of a laptop that can fit in the corresponding compartment of the backpack. Note that the average (standard) diagonal for modern laptops is 15.6", and most backpacks have a 15" laptop compartment. However, there are also more voluminous models that can accommodate a 17.3" or even 18.4" laptop. At the same time, compact models are also presented: there are backpacks with a compartment for a laptop 14", 13" and even smaller.

Note that the lack of a laptop compartment in itself does not prevent using a backpack to carry a laptop, however, in this case, the maximum allowable size of the device will have to be specified according to the dimensions of the backpack.