How to Tell a Turtles Age

Unless you have raised it from birth, it is nearly impossible to determine the exact age of a turtle. At best, you can make an educated guess based on a number of factors. And to make it all the more frustrating, a turtle's age becomes progressively harder to guess as it grows older.

Instructions

Difficulty: Moderate

1. Determine the species of the turtle in question, and learn the average adult size and life expectancy for that species.
2. Measure your own turtle, and make a rough estimate of its age, based on its present size. Make adjustments based on your turtle's gender: Female turtles grow larger than males.
3. Consider the life of the turtle. If your turtle was raised in captivity, subtract some years from your estimate: healthy, captive turtles grow faster than their wild counterparts. If your turtle has already bred, it must be sexually mature - but whereas water turtles become sexually mature as early as five years old, tortoises can mature as late as twenty.
4. Scrutinize the shell. Younger scutes (the external bony plate) will look new, whereas older shells won't show much growth. Furthermore, the shells of some species (such as the red-eared slider) get darker with age. Many younger turtles still possess distinct markings on their shells, which smooth with age. On top of that, older turtle shells are slower to heal from scratches, chips and general wear.
5. Considering all of these factors, make your final estimate.

Tips & Warnings

• Some turtles may eat more vegetables as they age, but this is not a hard and fast rule.
• Do not determine your turtle's age based on the lines on their shells. This is not accurate: in one good year, a turtle can grow several lines.