Isaac vs Isai
American parents have registered 332,292 Isaacs since 1880, against 7,385 Isais. Isaac is still ahead, with 5,963 babies in 2025.
Babies given each name, 1880–2025
Isaac Isai
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
Isaac has been the commoner name in every year either was published, 1880 to 2025. The lead has never changed hands.
The closest they came was 1990, when Isaac had 2,439 and Isai had 92.
Side by side
| Isaac | Isai | |
|---|---|---|
| Total US births | 332,292 | 7,385 |
| Most in one year | 10,287 | 333 |
| Babies in 2025 | 5,963 | 197 |
| Estimated living today | 300,000 | 7,300 |
| Median age today | 17 | 17 |
| Peak year | 2007 | 2007 |
| Best rank | 41st boys | 700th boys |
| Rank in 2025 | 47th | 1,138th |
| First recorded | 1880 | 1966 |
| Girls / boys | 784 / 331,508 | 45 / 7,340 |
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.
Where each one is strongest
- Isaac Nevada (2.2×), New Mexico (2.1×), Utah (2.1×)
- Isai Texas (4.0×), Arizona (3.7×), California (3.4×)
How much commoner the name is in that state than it is nationally, from births recorded since 1910.
Both names abroad
Countries whose statistics office publishes both names, so the comparison can be made somewhere other than the United States.
| Country | Isaac | Isai |
|---|---|---|
| England and Wales | 50,460 | 16 |
| France | 29,605 | 285 |
| Belgium | 2,107 | 25 Isaï |
| Switzerland | 1,039 | 23 |
Every spelling a country files separately is added together, over whatever years that country publishes — which is not the same range in any two of them, so read the columns against each other and not the rows.
Compare something else
Related comparisons
Social Security Administration birth records, 1880–2025, public domain. Full histories: Isaac and Isai.