The Fitzpatrick scale is a six-category system, developed by dermatologist Thomas Fitzpatrick in 1975, that classifies skin by how it responds to UV exposure rather than by color alone.
Why response to UV, not just color
Two people can have visually similar skin tone but burn at very different rates — the scale specifically measures burn and tan tendency (Type I always burns, Type VI never burns), which is more clinically useful than color alone.
Where it's actually used
Dermatologists use it to dose phototherapy treatments, predict sun-sensitivity, and assess skin cancer risk — it's a real clinical tool, not a marketing category invented for tanning apps.
How an app can estimate it
A combination of a short questionnaire (does your skin usually burn or tan, natural hair and eye color) plus a photo analysis can produce a reasonable estimate — though a formal clinical assessment by a dermatologist remains the most accurate method.
Is a self-assessed Fitzpatrick type as accurate as a dermatologist's?
Not necessarily — self-assessment and photo-based estimates are a useful starting point for general guidance, but a dermatologist's in-person assessment remains the clinical standard, especially if you have risk factors.