What is a typical length of a generation?

For census purposes, a generation is about 20 years. All people are grouped into roughly-20-year cohorts based on their birth year. That determines their generation.

Here are the generations identified by the Census Bureau:

New Worlders: 1871-1889

Hard Timers: 1890-1908

Good Warriors: 1909-1928

Lucky Few: 1929-1945

Baby Boomers: 1946-1964

Generation X: 1965-1982

New-Boomers: 1983-2001

20 years

A generation is defined as the average time between a mother's first offspring and her daughter's first offspring. In modern times, this would make a generation about 30 years.

A generation would be from birth to birth ... so how long it would take a child to have a child. On average, you're looking at about 23-27 years ... places like Denmark go up to about 30 years ... Africa can go as low as 16-18 years.

As many as 200 years in scripture. About 20 to 40 years.

In Hebrew tradition, a girl was to be married around age 13, then have children. So a generation was about 14-15 years.

In my family, it has been 19 years.

We almost always had 4 to 5 generations at the time.

A generation is normally considered to be 20 years.

That depends on what you mean by "generation", and please realize that it varies from culture to culture and it changes over time within a culture.

One of the medical definitions (I think this is the one you are seeking)

- The average interval of time between the birth of parents and the birth of their offspring.

Typically, when an average is desired it is somewhere between 20-30 years...but again: that can vary depending on culture and time period.

http://en.wikipedia.org/wiki/Generation_time

For humans, 20-25 years. For bacteria, it could be 2 weeks.