how can you tell how old a turtle is ?

Answer 1

cut off its trunk and count the rings

Answer 2

It's really hard, pretty much impossible, to gauge how old an adult turtle is. The growth rings on the shell (if they are even visable) aren't accurate because turtles can put down multiple rings in a year.

You can make a better guess with a young turtle, but growth is highly dependent of temperature and diet so these factors need to be considered. Some species, like red-eared sliders, become less colorful as they age. So if it is a large slider that is bright green, I would guess it is between 3 and 5 years old. A large slider that is brown, is probably older than that. A turtle that is very small, like an inch long, is very young. But again, if it's been kept in crappy conditions since hatching, it could be a year old but just never grew because wasn't cared for correctly.

Answer 3

There is no way to tell the age of a turtle for sure, unless you know it's birthdate, but you can make an educated guess if you know the basics. Read this to help;


How Old Is My Turtle?
=====================


Copyright by Valerie Haecky. This document may be freely
distributed for non-profit use, provided this notice is
included.


It is not possible to determine the exact age of a turtle
or tortoise unless you know its birthday.

You cannot determine a Chelonian's age by the rings on the scutes.
It may grow several rings in a good year when it is young
and growing fast, and no rings at all in a bad year or when
it is fully grown.

You can estimate a Chelonian's age in the following way. What you are
really doing is a bit better than guessing.

1) Find out what the adult size for the animal would be. (You need to know
the species for that, which is a good idea anyway, since different species
have vastly different requirments.)
2) Measure your turtle or tortoise.
3) Find out what the maximum age limit for the turtle or tortise would be.
(There are no exact numbers available, but water turtles generally live
to about 30-40 years, box turtles and tortoises to about 50-100 (and
longer in some documented cases.)
4) Guess based on size.
5) Subtract some years if the turtle was raised in captivity, because
captive turtles grow much faster because their diet is usually richer.
6) Look at the scutes. Has the turtle grown recently? You'll see growth
patterns that look new. A mature turtle grows slower and won't show much new growth.
7) Has the turtle bred? To do that, it must be mature. Water turtles become
sexually mature around 5-8 years of age, depending on species and environment.
(For tortoises it varies and can be as late as 20 years.)
8) For water turtles: Does the turtle eat/prefer vegetables? Older water
turtles eat more vegetables. (But that is not always true. I have a mature male
Reeves who eats no veggies, and a juvenile female Reeves who loves veggies.)
9) For red-eared sliders and Reeves turtles, the shell gets darker as the turtle gets older.
Dark shells are mature individuals. In many turtles and tortoises, the shell markings are
livelier and more pronounced in younger animals.
10) In younger animals, the growth patterns on the scutes are distinct, and the
scutes show more texture. In older animals, the shell gets smoother and may
be completely smooth in an old animal. (But, this varies with species and
environment.)
11) Know the gender of your turtle. Females usually grow bigger than males,
and a female will often be larger than a male at any given age.
12) Quality of shell. A mature turtle that grows slowly usually doesn't outgrow
scratches, pits, or chipped off pieces quickly, so older turtles, especially
in the wild, have more "stressed" shells.

Good Luck!

How Old Can Turtles and Tortoises Get?
=======================================

Like with all animals, different species and individuals within a
species can reach varying ages. There really are not any definite and
exact studies on longevity of Chelonians in the wild. There is
some information available on captive Chelonians when people
kept/keep records.

In general, water turtles are estimated to reach about 30-40 years of age.
Box turtles can get over a 100 years old but seem to range about 50-80 years.
Large tortoises have been known to get over 300 years old; a good assumption
for a tortoise is 50-100 years.
Sea turtle life span appears to be similar to humans.

Animals kept in captivity and under proper conditions (!!!)
live considerably longer than animals in the wild, because they
get veterinary treatment for diseases and parasites, and they
are protected from weather extremes and predators.

In any case, the most important thing to remember about how long
turtles and tortoises live is that they live for a very long time.
If you decide to keep Chelonians as pets, be willing and prepared
to provide for them for a long, long time; really, pretty much for
the whole of your life.

Answer 4

The only accurate way is to watch it be born.

For mating, etc., you can use a size chart that you can find for many species- not super accurate for age, but good enough for most care purposes.

For sheer curiosity, count the rings on the belly scales. Not really scientifically accurate, but close enough for most of our needs.

Answer 5

I think each "square" of her "shell" is formed by homocentrous squares, one for each year, like the rings of a tree. If you measure them you can find the age. But I am not sure.

Answer 6

wrinkles

Answer 7

see how big it was