What lengths do pet rats have? - briefly
Pet rats usually have a body length of 6–9 inches (15–23 cm) and a tail of comparable size, resulting in an overall length of roughly 13–20 inches (33–51 cm).
What lengths do pet rats have? - in detail
Pet rats typically reach a body length of 15–20 cm (6–8 in) when fully grown. The tail adds an additional 15–20 cm (6–8 in), resulting in an overall length of roughly 30–40 cm (12–16 in). Size varies with age, sex, and strain:
- Newborns: 5–7 cm (2–2.8 in) body length; tail proportionally shorter.
- Juveniles (4–8 weeks): rapid growth; body length 10–14 cm (4–5.5 in).
- Adult females: slightly shorter than males, averaging 15 cm (6 in) body length.
- Adult males: average 16–18 cm (6.3–7.1 in) body length.
- Fancy strains (e.g., Dumbo, hairless): may be up to 2 cm (0.8 in) longer or shorter than standard laboratory‑derived rats.
Tail length generally matches or exceeds body length, but some dwarf varieties possess tails 10–12 cm (4–4.7 in) long. Growth stabilizes around 6 months of age; after this point, length changes are minimal, though weight can fluctuate with diet and health.