A “normal” weight for a 12‑year‑old covers a wide range, and it depends on height, sex, and stage of puberty. Instead of aiming for one “right” number, doctors look at growth charts and BMI percentiles to see if a child’s growth is tracking in a healthy way.

Typical weight ranges

For many 12‑year‑old boys, a common weight range is roughly 67–130 pounds, with an average around 89 pounds. For many 12‑year‑old girls, a common range is about 68–135 pounds, with an average around 92 pounds.

Why there is no single “should”

Children hit growth spurts and puberty at different times, which can quickly change height and weight. Two 12‑year‑olds can weigh the same but have different heights and body compositions, so one might be in a healthy range while the other is not.

How doctors usually check

Health professionals use BMI‑for‑age percentiles (which compare weight to height and age) and growth charts from groups like the CDC. A weight between about the 5th and 85th percentile on those charts often counts as a “normal” range, but a doctor also considers diet, activity level, and overall health.

What you can do next

If you are worried about a specific 12‑year‑old’s weight, the safest step is to ask a pediatrician or family doctor and bring their exact height, weight, and age. The doctor can explain whether the current weight is healthy, and, if needed, suggest changes in eating habits, activity, or follow‑up checks.