Here's a breakdown:
* Kid: A goat from birth to about 6 months old.
* Yearling: A goat between 6 months and 1 year old.
* Adult: A goat between 1 year and 2-3 years old.
However, the exact age can vary based on factors like:
* Breed: Different breeds have different growth rates.
* Nutrition: Goats with good nutrition will grow faster.
* Gender: Males generally grow slightly larger than females.
Important note: While a goat may be fully grown physically at 18-24 months, their maturity and breeding potential may continue to develop for a few more months.