How big can a red eared slider grow?

Males-8-9inches

Females-up to 12 inches

No they will out grow their tank if it is too small.

May I suggest a smaller turtle such as a painted or a musk.

A female grows larger than a male. A female usually gets about 8-12 inches. A male usually about 8 inches. This depends on the environment that is provided. They need to live outdoors in a pond w/ filteration, rocks for basking, and some shade. You need to feed them a proper diet too. If your turtle lives indoors it needs a basking site w/ a reptile basking heat bulb, an ultraviolet light, filteration, a heater in water, and proper diet w/ added suffitient calcium and multivitamins. Every turtle varies in growth. How large is the turtle yoou have. If it's a juvenile, about 4 inches. It will grow to it's full size slowly. A two inch baby, however, will grow to about 4 inches in a year or two. Redears can live for well over 20 yrs so they grow slowly. Please read about their proper care, ect. before you purchase one if you are thinking about buying one. Turles that do not receive the proper lighting, vitamins, etc. will develop calcium deficientcy, eye problems, and stunted growth, just to name a few

8-12 inches is about right depending on nutrition, you will either have to get a giant 50 gallon tank or have it live in an outdoor pond. Many people do not realize that they grow so big and live for so long (up to 50 years) and the commitment they require!

8-12 inches in diameter across the shell. Do not believe the myth that RES turtles only grow to the size of their tank. They will continue to grow and will suffer damage to their shell.

I had one that grew bigger than the top of a bar school (12 inches at least). He currently lives happily in my friends pond considering he is way to big for any tank.

I have one and she is 18 she is a little smaller than the lid of an ice cream tub. No they don't grow smaller with what cage they have because she had a smaller cage when i first got her but she outgrew it. :)

males tend to grow about ten inches and females about twelve inches...

it doesn't matter... turtles still grow..