How Fast Do Turtles Grow (A Guide With Charts)

How fast do turtles grow? It depends on species, care, and age. Use the species charts on this page to get a good estimate, then plan tank size and diet so your turtle grows at a healthy pace.

How to measure for these charts

Measure the carapace straight across from the front notch to the back edge. Do not follow the curve. Write the length in inches or centimeters and match it to the chart for your species. Growth also depends on diet, UVB, temperature, sex, and habitat size, so treat the result as a range.

Table Of Contents

1. How Fast Do Red Eared Sliders Grow
2. How Fast Do Painted Turtles Grow
3. How Fast Do Snapping Turtles Grow
4. How Fast Do Map Turtles Grow
5. Factors That Affect a Turtle’s Growth Rate

Growth rate of popular pet turtle species

How Fast Do Red Eared Sliders Grow

Short answer. Expect about 3 to 4 cm in the first year, around 6 cm by year two, and close to 10 cm by year three. Many reach full size in about eight years.

Red eared sliders grow the fastest within the first few years. By year one many reach 3 to 4 cm. By year two they are close to 6 cm. By year three they are near 10 cm. Males often breed at about 10 cm and females at about 15 cm which many reach around five to six years. Adults usually end up between 18 and 30 cm.

Red eared slider growth chart

Age	Average shell length (cm)
1	4
2	6
3	10
4	11.5
5 to 6	15
Adult	18 to 30

How Fast Do Painted Turtles Grow

Short answer. Juveniles average about 1.2 cm of growth per year. After maturity around age ten growth slows a lot.

Painted turtles grow fastest as juveniles. By age one many reach about 5 cm. By age two they are near 7 cm. By age ten many are around 12 cm and keep climbing slowly to about 15 cm on average. Adults range from 10 to 25 cm depending on subspecies and care.

Painted turtle growth chart

Age	Average shell length (cm)
1	5
2	7
4	8
10	12
20	15

How Fast Do Snapping Turtles Grow

Short answer. In the first two years many reach 12 to 15 cm. After maturity growth slows, and large adults can reach 45 cm with the right care and time.

Snapping turtles are heavy eaters in captivity and can grow quickly when food and heat are abundant. In the first two years the common snapping turtle often reaches 12 to 15 cm. Over the next years growth slows a lot. Big adults can reach about 45 cm and heavy weights.

Snapping turtle growth chart

Age	Average shell length (cm)
2	12
Adult	up to 45

How Fast Do Map Turtles Grow

Short answer. Males stay small at about 10 cm carapace when grown. Females reach about 18 to 25 cm. Early growth is steady, then it slows near maturity.

Map turtles show strong size differences between sexes. Hatchlings start small. By year one many are near 4.2 to 4.4 cm plastron length. By year four males average about 7.6 cm plastron while females average about 9.6 cm. Males top out near 8 to 9 cm plastron and females near 14 to 18 cm plastron which lines up with about 10 cm and 18 to 25 cm carapace for adults.

Map turtle growth chart

Age	Male plastron (cm)	Female plastron (cm)
1	4.2	4.4
2	6	6
4	7.6	9.6
5	8.1	11
7	8.4	14
10	—	18

How Fast Do Box Turtles Grow

Box turtles grow fastest from zero to five years at about 1 cm per year. From five to ten years growth slows to about 0.8 cm per year. From ten to fifteen it slows again to about 0.2 cm per year. Hatchlings are about 2.5 cm. By age five many reach about 7.5 cm and by age ten near 12.3 cm. Adults often measure 12.7 to 15 cm.

Factors That Affect a Turtle’s Growth Rate

Healthy diet

Feed for the species and life stage. What do turtles eat gives a full breakdown. Painted turtles do well with about 30 to 40 percent protein when young. Box turtles need more protein as juveniles. Keep portions sensible since overfeeding causes rapid growth and health issues.

Genetics and sex

Species and sex matter. Two turtles of the same species raised the same way can still grow at different speeds. Check our guide to tell a turtle’s gender.

Environment

UVB, clean water, space, basking heat, and safe hides all support steady growth. Lack of UVB can lead to pyramiding and metabolic bone disease. Keep the enclosure big enough. A common rule is ten to fifteen gallons of water per inch of shell for aquatic turtles.

Conclusion

Measure the shell the same way each time and use the charts here to get a solid age range. Plan ahead so the tank and diet match the next growth stage. If your turtle grows faster or slower than the chart, that is normal. Use the ranges and focus on steady, healthy progress.