Blue Tongue Skink Size & Weight Chart by Age

Last updated: · Reviewed against sources listed below

This blue tongue skink growth chart shows typical weight and length by age. Newborns measure about 5 inches and weigh around 14 grams, and northern blue tongues reach 280–510 grams and about 15–24 inches as adults.

Measure by

Weigh on a kitchen scale before feeding.

This is our reptile age and growth estimator, preset for blue tongue skinks.

Blue Tongue Skink growth chart by age

Blue tongues grow fast in their first year when well fed. Weight is the most useful measure, so treat these as broad ranges. Use the °F / in button at the top of the page to switch to centimeters.

AgeTotal lengthWeight
Hatchling4–6 in10–15 cm10–20 g (0.35–0.71 oz)10–20 g
3 months7–10 in18–25 cm40–90 g (1.4–3.2 oz)40–90 g
6 months10–14 in25–36 cm100–200 g (3.5–7.1 oz)100–200 g
12 months14–18 in36–46 cm200–350 g (7–12 oz)200–350 g
18 months15–21 in38–53 cm250–450 g (9–16 oz)250–450 g
2 years15–24 in38–61 cm280–510 g (10–18 oz)280–510 g

How big do blue tongue skinks get?

Northern blue tongues are the largest and heaviest of the pet types. Adults average about 17 inches from snout to tail tip, can reach about 22–24 inches, and usually weigh 280–510 g (10–18 oz)280–510 g. Other types are a little smaller.

Blue tongues are born live rather than hatching from eggs. Newborns are already about 5 inches long and weigh around 14 grams. When food is plentiful they grow very quickly and can reach adult size in under a year, then fill out over the next year or two. They are usually sexually mature at 2–3 years.

Weighing your skink

Weigh your skink every two to four weeks, at the same time of day and before a meal, on a digital kitchen scale that reads in grams. A lidded box or tub on the scale keeps it still. Keep a log so you can spot changes early.

A healthy blue tongue has a thick, rounded body and a tail about as wide as its body at the base. A thin, bony tail base or visible hip bones suggest it is underweight; fat pads around the legs or a very wide belly suggest too much food.

Why is my skink growing slowly?

  • Not enough protein for a young skink, or meals too far apart.
  • A cool basking spot. Below about 92°F33°C, digestion and appetite slow down.
  • Seasonal slowdowns in the cooler months.
  • Missing UVB or calcium, which can lead to metabolic bone disease.
  • Parasites or illness. A vet check and fecal test can rule these out.

See a reptile vet if your skink is losing weight, has a soft or swollen jaw, bent limbs or tremors, or struggles to walk. These can be signs of metabolic bone disease.

Frequently asked questions

How fast do blue tongue skinks grow?

Very fast in the first year. A well-fed northern blue tongue can grow from about 14 g at birth to 100–200 g by 6 months and 200–350 g by a year, then fill out to 280–510 g by about two years. Feeding, temperature and UVB all affect the rate.

How can I tell if my blue tongue skink is male or female?

It is hard to tell by looking. Males often have a broader head and a thicker tail base, but these clues are unreliable. A reptile vet can sex a skink by probing or with an ultrasound or X-ray. Many owners only find out when a female gives birth or a male shows mating behavior.

At what age is a blue tongue skink fully grown?

Blue tongues can reach adult length in under a year when well fed, but they keep filling out until about two years old. They are usually sexually mature at 2–3 years. After that, weight changes mostly reflect feeding and body condition.

Sources

Where sources disagree we show the range they share. See our sources and methodology for how every number is checked.

Results are estimates for healthy animals. Always consult a reptile veterinarian for individual advice. Read our disclaimer.

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