The Beaver is functionally shaped in order to accommodate a useful and sizable payload, typically close to , even when equipped with floats. While the front doors are narrow, the aft doors are wider, having been designed to facilitate the loading of 55-gallon barrels, either upright or on their sides. The Beaver is considered a 'working' aircraft, which was designed for vigorous use. In addition to cargo, passengers can also be carried; when appropriately fitted out, the Beaver Mk.I can accommodate up to seven passengers while the more spacious Beaver Mk.III can hold a maximum of 11. Various alterations have been approved, including alternative seating arrangements, enlarged cargo doors, larger windows and smaller batteries have been approved for use.