how long is a generation

A “generation” is usually taken to be about 20–30 years, with many modern sources centering on roughly 25–30 years for humans.

What “generation” means

• In family and biology contexts, a generation is the average time from a person’s birth to the birth of their child.

• In everyday modern use, dictionaries and popular explanations often define it as “about 20–30 years” during which children are born, grow up, and begin having children of their own.

Why the number varies

Different fields and eras use slightly different numbers:

• Demography/biology: Human generation time is typically described as ranging from 20 to 30 years, depending on gender and society.

• Modern everyday use: Many articles and guides round this to “about 25 years,” sometimes stretching to 30 years for simplicity and to match current later parenting ages.

• Earlier historical periods: In many past societies, people tended to have children younger, so the effective average generation length was closer to the low‑20s.

Common working averages

When people need a single, practical number (for rough timelines, genealogy, or loose historical estimates), they often use:

• 25 years per generation as a simple rule of thumb.

• 30 years per generation when aligning with modern patterns of later childbearing or when being conservative for genealogical time spans.

So if you just need a handy, everyday answer: think of a human generation as about 25 years, with 20–30 years being the realistic range.

Information gathered from public forums or data available on the internet and portrayed here.