 "Vespadelus douglasorum" is distinguished by the length of forearm to 34.3 to 37.8 mm.total of head and body 35 to 44 mm, length of tail 35 to 38 mm and a length from notch at base to the tip of ear is 11 to 12.5 millimetres.The sample range in weight of 4.5 to 6 g averaged to a mean of 5.3 grams.