The normal size of a human uterus is typically 8 to 10 centimeters long by 6 centimeters wide, or 3 to 4 inches by 2.5 inches, according to the National Uterine Fibroids Foundation. The shape of the uterus is like an upside-down pear.
The normal thickness of the uterus is around 3 centimeters with an average weight of 60 grams. MDhealth.com explains that the uterus can weigh up to 200 grams depending on various conditions. Enlargement of the uterus can occur due to pregnancy, endometriosis, uterine fibroids, the menstrual cycle and during contraceptive use. According to WebMD, a woman's uterus can grow to the size of a watermelon during the final weeks of pregnancy.