How to read the band →
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).
Carl
Carl is now well below its former popularity. All-time it's been given to 609,768 U.S. babies, the 1,370th most common name by sound today, peaking at 10,566 in 1957, with 294 in 2025.
By sound, Carl also includes the spellings Karl.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).