Of the species of Batomys known to live on Mount Isarog, the large-toothed hairy-tailed rat (B. dentatus) is distinct. But B. granti is basically similar to B. uragon. B. uragon differs from B. granti in slightly larger body, longer legs, but shorter tail, and larger skull. Males are larger than females. Males measure 19.83 cm in length, while females are 18.82 cm, a centimetre smaller. This sexual dimorphism is almost absent in B. granti, as both males and females are about 19 cm long. The tail length is 14.4 cm in males, and 14.16 cm in females. The total body weight is 178 g for males, and 177 g for females. Karyotype shows that it has 52 chromosomes (haploid, n=26). The colour of the fur is pale golden-brown. There are colour variations in individuals. One male specimen has a small pale brown patch of fur on the left side of the lower abdomen. The holotype has a pale golden fur, paler than other specimens.