Solid line = floor (spellings that unambiguously belong to the group). Shaded band up to the dashed edge = ceiling (the most it could reach if every ambiguous spelling counted here).
Michael is down from its peak but still widely used. All-time it's been given to 4,624,701 U.S. babies, the 37th most common name by sound today, peaking at 98,063 in 1957, with 8,386 in 2025.
By sound, Michael also includes the spellings Micheal, Michal, Mykel, Mikal, Michale. Spellings sometimes heard the same way: Mikel.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).