Of all boys' first names in the United States, about 1.5 % begin with the letter I…
This means that the initial I is found much less frequently than average. On average, each letter appears as an initial in about 3.8 % of all boys' names, considering the 26-letter English alphabet. Of course, first letters aren't (exactly) evenly distributed as initials: On the contrary, some initials are especially common, while others are really rare. The most common initials among boys' first names in the United States are J and A, while fewer
boys' names begin with the letters U and X.
In the US, Isaac is currently the number 1 most popular boys’ name to start with an I. In second and third place are names such as Isaiah and Ian. A far rarer name starting with I in the US is Ismael.