Corn Snake Size & Weight Chart by Age
Last updated: · Reviewed against sources listed below
This corn snake growth chart shows typical weight and length by age. Hatchlings measure about 8–15 inches and weigh 6–12 grams, and most corn snakes reach 3–5 feet and 300–900 grams as adults.
Estimate
- Estimated age
- Normal range for that age
- Compared with normal
This is our reptile age and growth estimator, preset for corn snakes.
Corn Snake growth chart by age
Weight is the most useful measure for snakes. Growth depends heavily on how often a snake eats, so treat these as broad ranges. Use the °F / in button at the top of the page to switch to centimeters.
| Age | Total length | Weight |
|---|---|---|
| Hatchling | 8–15 in20–38 cm | 6–12 g (0.21–0.42 oz)6–12 g |
| 3 months | 12–18 in30–46 cm | 12–30 g (0.4–1.1 oz)12–30 g |
| 6 months | 16–24 in41–61 cm | 25–60 g (0.9–2.1 oz)25–60 g |
| 12 months | 2–3 ft61–91 cm | 50–150 g (1.8–5.3 oz)50–150 g |
| 18 months | 2.5–3.5 ft76–107 cm | 120–300 g (4–11 oz)120–300 g |
| 2 years | 3–4 ft91–122 cm | 200–500 g (7–18 oz)200–500 g |
| 3 years | 3.5–5 ft107–152 cm | 300–900 g (11–32 oz)300–900 g |
How big do corn snakes get?
Adult corn snakes usually measure 3–5 ft91–152 cm and weigh 300–900 g (11–32 oz)300–900 g. The species can range from about 2 feet to about 6 feet, but most pet corn snakes end up in the 3–5 foot range. Males are often a little longer and heavier than females.
Corn snakes grow fastest in their first year and reach adulthood around 1.5–2 years old. Maturity depends on size more than age; a corn snake is usually able to breed at about 30 inches or 250 g. Growth continues slowly for a few more years after that.
Tracking your corn snake’s weight
Weigh your snake in grams every two to four weeks, before a meal. Place it in a lidded container on a digital kitchen scale and subtract the container’s weight. Keep a log alongside feedings; the feeding calculator can print one for you.
Look at body shape too. A healthy corn snake has a rounded, slightly loaf-shaped body. A sharp ridge along the spine suggests it is underweight, while fat folds when it bends suggest it is overweight.
Why is my corn snake growing slowly?
- Prey that is too small or too infrequent for its weight.
- Low temperatures. A warm end below about 85°F29°C slows digestion and appetite.
- Seasonal slowdowns. Many corn snakes eat less in winter.
- Stress from a lack of hides, an open enclosure or frequent handling.
- Parasites or illness. A vet check and fecal test can rule these out.
If your corn snake is losing weight rather than just growing slowly, or shows signs such as wheezing, mucus or swelling around the mouth, see a reptile vet.
Frequently asked questions
How fast do corn snakes grow?
Most corn snakes grow from about 6–12 g at hatching to 50–150 g by their first birthday and 200–500 g by age two. Growth then slows. Feeding frequency and temperature affect the rate a lot, so two healthy snakes of the same age can be very different sizes.
How do I know if my corn snake is underweight?
An underweight corn snake has a visible ridge along its spine, a triangular cross-section and sometimes loose skin. Compare its weight with the chart for its age, and check that it eats regularly. If it is thin and refusing food, or losing weight, have a reptile vet check it for parasites or illness.
At what age is a corn snake fully grown?
Corn snakes are usually adults at about 1.5–2 years old, once they reach around 30 inches or 250 g. They keep growing slowly for a few more years and often reach full size by about 3 years. After that, weight changes mostly reflect feeding and body condition.
Sources
- ReptiFiles — Corn Snake Care Guide
- Wikipedia — Corn snake
- Cornsnakes.com forum — Length, weight and age data from keepers
- PetMD — Corn Snake Care Sheet (written by a veterinarian)
Where sources disagree we show the range they share. See our sources and methodology for how every number is checked.