Boys' name · peaked in 1951
Rex name popularity since 1925
53,349 babies born in the US from 1925 to 2025 were named Rex. Half of them were born in 1958 or earlier, so the typical Rex is about 68 years old in 2026. Rex peaked in 1951 as the #170 name for boys, and it ranked #859 in 2025.
Key facts
- US babies since 1925
- 53,349
- Named Rex, 1925–2025
- In 2025
- #859
- for boys in 2025 (281 babies)
- Girls / boys
- 99.8% boys
- 131 girls · 53,218 boys
- Most popular in
- Utah
- 3.44× its national share
Peak year is the year Rex made up the largest share of US boys, in records going back to 1880. Typical age is based on births from 1925 on, not on who is living today.
Rex births per year, 1925–2025
1951 was the biggest year for Rex both by count and as a share of all babies.
- Steepest fall: Between 1964 and 1969, Rex's share of baby boys fell by 44%, from 1 in 2,080 to 1 in 3,740.
- Fastest rise: Between 2000 and 2005, it became 2.1× more common, from 1 in 17,500 baby boys to 1 in 8,430.
Shaded on the chart. Both compare Rex's share of all US boys five years apart, counting only years with at least 100 babies named Rex.
Decade by decade
Babies named Rex in each decade, and its rank among boys' names in the middle year of the decade (1935, 1945 … 2025).
| Decade | Girls | Boys | Rank |
|---|---|---|---|
| 1925–29 | 23 | 2,634 | – |
| 1930s | 12 | 5,949 | #198 |
| 1940s | 11 | 6,671 | #269 |
| 1950s | 44 | 13,499 | #191 |
| 1960s | 23 | 8,735 | #264 |
| 1970s | 7 | 3,359 | #469 |
| 1980s | 11 | 2,532 | #545 |
| 1990s | 0 | 1,740 | #869 |
| 2000s | 0 | 2,048 | #808 |
| 2010s | 0 | 3,945 | #680 |
| 2020–25 | 0 | 2,106 | #859 |
Ranks count every name given to at least 5 boys that year, so they can go past 1,000.
Generation fingerprint
42.3% of babies named Rex from 1925 to 2025 were born in the Baby Boom years (1946–1964). The full split by generation:
Where Rex is most popular
The index compares Rex's share of babies in each state with its share nationwide, 1925–2025 (1.50× = 50% more common). States with at least 300 babies named Rex.
| State | Index | Babies |
|---|---|---|
| Utah | 3.44× | 1,458 |
| Kansas | 3.27× | 1,662 |
| Indiana | 3.03× | 3,572 |
| Idaho | 2.98× | 590 |
| Nebraska | 2.92× | 1,019 |
Names with a similar story
Of the other 1999 names on this site, these six had the share of babies closest in shape to Rex's from 1925 to 2025, however common each one got. Each line is scaled to its own high; the dashed line is Rex.
Names from the same era
Other common names that peaked within two years of Rex (1951).
Source: U.S. Social Security Administration national and state baby-name data, which covers names given to at least 5 babies of one sex in a year. About the data