How old is someone named Theo?
The average Theo is 10 years old.
Half of all living Theos are between 3 and 9.
When was Theo popular?
Theo has been rising for years and peaked in 2023, so most Theos are still kids.
Popular names of 2023 · The most popular names of the 2020s →
Show the numbers by decade
| Born in | Babies born | Alive today |
|---|---|---|
| 1900s | 522 | 0 |
| 1910s | 1,447 | 0 |
| 1920s | 1,845 | under 100 |
| 1930s | 1,045 | 150 |
| 1940s | 766 | 370 |
| 1950s | 545 | 380 |
| 1960s | 390 | 320 |
| 1970s | 405 | 370 |
| 1980s | 540 | 510 |
| 1990s | 605 | 580 |
| 2000s | 1,391 | 1,400 |
| 2010s | 8,245 | 8,200 |
| 2020s | 21,036 | 21,000 |
How many Theos are still alive?
About 33,000 Theos are alive in the US today. That's 84% of the roughly 39,000 babies named Theo since 1880.
Most Theos ever born are still alive.
What generation is the name Theo?
About nine in ten living Theos are in Gen Alpha, born in 2013 or later.
Is Theo an old name?
No. Theo is one of the youngest names around: younger than 95 in 100 names on AgeByName.
Looking ahead: if babies keep getting the name at today's pace, the typical Theo will be 20 in 2056, so the name is aging slowly.
Is Theo a boy or girl name?
Mostly boys: 97.6% of living Theos are men.
Names the same age as Theo
NAME TWIN
Theo's name twin is Magnolia. Of all 3,713 names on AgeByName, Magnolia's age curve is the closest match to Theo's: 92% alike.
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Questions about the name Theo
How old is the average Theo?
The average Theo in the US is 10 years old. The median is 5, so half are older and half younger.
How many people are named Theo?
About 33,000 Theos are alive in the US today, out of roughly 39,000 babies given the name since 1880.
When was the name Theo most popular?
In 2023, when about 4,200 baby boys were named Theo.
Is Theo a Gen Alpha name?
Yes. About 86% of living Theos are in Gen Alpha, born in 2013 or later.
Estimates from Social Security Administration baby-name records (births 1880–2025) and SSA cohort life tables (2026 Trustees Report). Updated each spring. How we calculate this