It depends on how big your pockets are....
I have the P20 Lite (7.62cm smaller) and it fits well in my pocket.

My Galaxy tab s2 8" tablet surprisingly fits even in most jacket pockets. It also fits in large pockets, but is uncomfortable to walk around with. So I usually keep it in the front pocket of my Friday bag.

The Galaxy Note 3 5.7", on the other hand, fits well in the back pockets of trousers, but I don't do that often to avoid sitting on it.