Rat Terrier Weight & Growth Chart

Complete weight guide with growth charts for male and female Rat Terriers from puppy to adult.

Male Adult Weight
10–25 lbs
Female Adult Weight
8–22 lbs

Rat Terrier Weight Overview

Weight range for the Rat Terrier: 10–25 lbs overall. Males: 10–25 lbs. Females: 8–22 lbs.

Come in two sizes: miniature at 10 to 18 pounds and standard at 22 to 25 pounds, both standing proportionally at 10 to 18 inches tall.. Consult the growth chart below for typical weight progression by age.

Growth Chart

When Does a Rat Terrier Stop Growing?

Expect your Rat Terrier to reach adult height of 10–18 inches by 12–15 months. Full body maturity—including muscle development toward the 10–25 lb target—may continue until 14–18 months.

Growth is influenced by genetics, nutrition quality, and spay/neuter timing. Generally one of the healthier terrier breeds with fewer genetic issues, though patellar luxation remains a common orthopedic concern to screen for..

Is My Rat Terrier Overweight?

Assessing your Rat Terrier's body condition (healthy range: 10–25 lbs):

  • Rib check: Run your hands along the ribcage—you should feel individual ribs under a slight fat layer
  • Overhead view: A defined waist should be visible between ribs and hips
  • Side profile: The abdomen should tuck upward behind the last rib

Overweight Rat Terriers face higher risks of Patellar Luxation, joint problems, and shortened lifespan. Even for a small-sized breed, excess weight significantly impacts joint health and overall wellbeing. Work with your vet to adjust feeding and exercise if needed.

Feeding Recommendation

Daily food for an adult Rat Terrier: 0.5–0.5 cups of high-quality dry food in two meals, budgeting $42–67/month. Puppies growing toward 10–25 lbs need three to four daily feedings until around six months old. Generally one of the healthier terrier breeds with fewer genetic issues, though patellar luxation remains a common orthopedic concern to screen for.—treats count toward daily calorie intake.

Weight by Age Table

AgeMale (lbs)Female (lbs)
3 months 5.5–7.0 4.7–5.9
6 months 12.1–15.4 10.3–13.1
9 months 17.7–22.3 15.0–19.0
12 months 22.1–27.9 18.7–23.8

Frequently Asked Questions

Adult Rat Terriers weigh 10–25 lbs (males: 10–25 lbs; females: 8–22 lbs). Come in two sizes: miniature at 10 to 18 pounds and standard at 22 to 25 pounds, both standing proportionally at 10 to 18 inches tall..
Height plateaus around 12–15 months for the Rat Terrier, with males reaching 25 lbs and females 22 lbs at maturity. As a terrier breed originally from United States, they were bred for a compact, sturdy build.
Three quick checks for your Rat Terrier: (1) Feel the ribs–they should be easily palpable under a thin fat layer. (2) View from above–there should be a visible waist behind the ribs. (3) Side profile–the abdomen should tuck up. Target weight: 10–25 lbs. Their coat type allows for relatively easy visual body condition assessment. Consult your vet for a body condition score.
Feeding amounts depend on age, current weight, and the Rat Terrier's expected adult size of 10–25 lbs. Puppies under 6 months need 3–4 meals daily; older puppies eat twice daily. A high-quality puppy food formulated for small breeds provides the right nutrient balance. Generally one of the healthier terrier breeds with fewer genetic issues, though patellar luxation remains a common orthopedic concern to screen for..
Poor weight gain in a Rat Terrier puppy warrants a vet visit. For a breed that should reach 10–25 lbs at maturity, slow growth can signal parasites (very common in puppies), underfeeding, food intolerance, or illness. Regular weigh-ins help track progress objectively. Your vet will likely run a fecal test and blood work.