Theo vs Thera
American parents have registered 39,333 Theos since 1880, against 892 Theras. Theo is still ahead, with 3,966 babies in 2025.
Babies given each name, 1880–2025
Theo Thera
Each line is every baby given the name that year, girls and boys added together — the only count that means the same thing for both names. A line breaks where the name fell below five babies in a year — the point at which the SSA stops publishing it — rather than being drawn through a figure nobody published. A single published year in a gap shows as a dot.
Who was ahead
Of the 146 years in which either name was published, Theo for 144 years and Thera for 2 years. The lead changed hands 2 times.
Side by side
| Theo | Thera | |
|---|---|---|
| Total US births | 39,333 | 892 |
| Most in one year | 4,182 | 31 |
| Babies in 2025 | 3,966 | under 5 |
| Estimated living today | 33,000 | 450 |
| Median age today | 4 | 46 |
| Peak year | 2023 | 1982 |
| Best rank | 78th boys | 2,901st girls |
| Rank in 2025 | 82nd | unranked |
| First recorded | 1880 | 1899 |
| Girls / boys | 3,503 / 35,830 | 892 / 0 |
A rank is a position within one sex’s list for one year, so the two rank rows are not subtracted from one another and the winning column is not marked on them. The living figure is a life-table estimate, not a count.
Which name is older
Half of the Theras alive today are over 46; half the Theos are over 4. That is 42 years between them: two names in use at the same time, worn by two different generations.
Compare something else
Related comparisons
Social Security Administration birth records, 1880–2025, public domain. Full histories: Theo and Thera.