Generations by Birth Year: Boomers, Gen X, Millennials and Gen Z

In the United States, the most widely cited generation birth years come from Pew Research Center: the Silent Generation was born from 1928 to 1945, Baby Boomers from 1946 to 1964, Generation X from 1965 to 1980, Millennials from 1981 to 1996 and Generation Z from 1997 onward. Children born since the early 2010s are usually called Generation Alpha.

Only one of those ranges is official in any sense. The rest are research conventions, which is why a quick search can return several answers for the same birth year. The table below this guide lists the standard ranges. The sections here explain where the names came from, why the boundaries move and how to place a specific birthday.

The generations and their ages in 2026

Ages here are the ages people reach during 2026, using Pew’s ranges.

• Greatest Generation: born before 1928. The youngest members turn 99 in 2026.
• Silent Generation: born 1928 to 1945. They turn 81 to 98 this year.
• Baby Boomers: born 1946 to 1964. The oldest turn 80 in 2026 and the youngest turn 62.
• Generation X: born 1965 to 1980. They turn 46 to 61.
• Millennials: born 1981 to 1996. They turn 30 to 45.
• Generation Z: born from 1997. Using the commonly quoted end year of 2012, they turn 14 to 29.
• Generation Alpha: born from about 2010 or 2013, depending on the source, into the mid-2020s.

The Baby Boom is also the easiest generation to measure. Pew counts about 76 million births during the boom. Annual US births passed 4 million in 1954 and stayed above that level through 1964. The Boomer population peaked at about 79 million in 1999, helped by immigration, and stood near 67 million in 2024, about 20 percent of the country. At its peak share in 1964, the generation made up 37 percent of the population.

Where the generation names came from

None of the names were chosen by a government agency. They spread through journalism, books and research:

• Greatest Generation. The label for Americans who came of age during the Depression and World War II was popularized by Tom Brokaw’s best-selling book The Greatest Generation.
• Silent Generation. Pew credits Time magazine with coining the term in a 1951 article about the young adults of that era.
• Baby Boomers. The name describes the demographic event itself: the jump in births after World War II.
• Generation X. The group was briefly called the “Baby Bust.” The Gen X label took over after Douglas Coupland’s 1991 novel Generation X made it popular.
• Millennials. Some writers called them Generation Y when they first reached adulthood, and early definitions used slightly different years.
• Generation Z. The name continued the alphabet after X and Y. Pew says it hesitated to name the group at first, then adopted Generation Z in 2019.
• Generation Alpha and Beta. The Australian research firm McCrindle named these groups, switching to the Greek alphabet after Z.

Why generation boundaries vary

The Baby Boom has a demographic boundary. Pew describes it as the only generation officially designated by the US Census Bureau, defined by the surge in births that began in 1946 and the significant drop after 1964. Its edges come from birth counts, not opinion.

Every other boundary is a judgment call. Researchers look for shared formative experiences and pick a year that separates people who lived through them at a similar age. Pew explained its choice of 1996 as the last Millennial year with a few examples:

• Most Millennials were between 5 and 20 years old during the September 11, 2001 attacks, old enough to remember them. Most of Gen Z has little or no memory of that day.
• Most Millennials were 12 to 27 during the 2008 presidential election.
• Many Millennials entered the workforce during the Great Recession.
• When the iPhone launched in 2007, the oldest members of Gen Z were 10.

Pew itself says generational cutoff points “aren’t an exact science” and describes them as tools for analysis. A typical generation spans 15 to 18 years, which is long enough to hold very different experiences.

Other organizations draw the lines elsewhere. McCrindle uses fixed 15-year blocks: Generation Z from 1995 to 2009, Generation Alpha from 2010 to 2024 and Generation Beta from 2025 to 2039. Its stated reason is consistency, so analysts can compare generations of equal length across countries. Under those rules, someone born in 1995 is Gen Z, while Pew would call the same person a Millennial.

Worked examples: which generation is that birth year?

Born in 1964 or 1965. Pew and the Census Bureau’s baby boom definition both end with 1964 births. A person born on December 31, 1964 is a Boomer; a person born the next day, January 1, 1965, is Gen X under Pew’s ranges. The label changes overnight even though the two grew up in the same years.

Born in 1980 or 1981. This is the Gen X and Millennial line. Someone born in 1981 was 19 or 20 on September 11, 2001, depending on the birthday, while someone born in 1980 was 20 or 21. On the same day, a person born in 1990 was 10 or 11. Seeing the ages side by side shows why the edges of a generation have more in common with each other than with the middle of their own groups.

Born in 1995. Pew: Millennial, because 1995 falls before the 1996 cutoff. McCrindle: Gen Z, because its Gen Z begins in 1995. Neither answer is wrong. They come from different systems.

Born in 2010. Pew: Generation Z, if the commonly used 1997 to 2012 range applies. McCrindle: Generation Alpha. The question is still open partly because this group is so young: a child born in 2010 was 8 or 9 when Pew set its Millennial cutoff in 2019. The 2012 calendar marks the year most often used as Gen Z’s last.

To work out an exact age on a specific date, such as someone’s age on the day of a historic event, use the age calculator.

Cuspers: born near a boundary

A cusper is someone born within a few years of a generational cutoff. People born around 1980, for example, often say they relate to both Gen X and Millennials. That reaction fits the evidence: a single cutoff year cannot capture a gradual change in experiences.

Cuspers are one reason Pew changed its approach in 2023. Pew now uses generational labels only when it has comparable historical data and when the label adds value. Otherwise it may group people by birth decade, by their age when a key event happened or by the first presidential election in which they could vote. Pew has also warned that broad labels can reinforce stereotypes and hide large differences within a generation.

If you were born near a boundary, a practical approach is to ask what you actually remember. Someone born in 1996 or 1997 can check the 1996 calendar and the 1997 calendar, then compare their age during events such as the 2001 attacks or the 2007 iPhone launch with Pew’s reasoning above.

Using generations in family and historical research

Generation labels are handy shorthand when you sort family photos or write a family history, but birth years carry more information than the label does. For a grandparent born in 1946, the useful facts are that they were a child in the 1950s, a teenager in the early 1960s and old enough to be drafted during the Vietnam War. For a parent born in 1981, the useful facts may be that they turned 20 in 2001 and were in their late 20s during the 2008 financial crisis.

Our guide to what happened on the day you were born shows how to research a specific birth date. For the zodiac animal that matches the same birthday, see Chinese zodiac years.