How big do crested gecko get?

The average size is about 8 inches.
The Average Female crested gecko will grow up to 10" (with tail) and reach 35-45Grams.

The average Male crested gecko will grow up to 10" (Give or take an inch) and reach 30-40Grams.

There are well known breeders with males reaching 62Grams and Females topping 75Grams!!
Female crested geckos can reach lengths of 8-10" and weigh in around 45-55 grams. A male crested gecko can reach lengths of 8-10" and weigh in around 35-45 grams.