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).
Hayden is down from its peak but still widely used. All-time it's been given to 157,620 U.S. babies, the 223rd most common name by sound today, peaking at 9,208 in 2008, with 3,188 in 2025.
By sound, Hayden also includes the spellings Haiden, Haden.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).