How long does it take for a guinea pig to grow up?

Guinea pigs generally reach adulthood around 5 to 6 months, with adult body length 15 to 20 cm and some reaching 30 cm. They mature sexually early, at 2 to 3 months, but it is recommended to wait until 6 months before breeding.

Guinea pigs breed strongly, with an estrus cycle of about 16 days and a gestation of about 68 days, and can breed again soon after birth, but frequent breeding harms the female’s health, so it is generally not recommended.