Please tell me what age is puberty considered late for guys?

Generally after 14: Generally, if a boy hasn't started puberty by 14, it is worth seeing a physician to discuss it. Everyone develops at his own pace, though that's usually little comfort for those who start developing later. Most kids have annual physicals for sports or school, and part of that exam is checking for normal growth and development. It's a good time to ask those types of questions.