UV Index and Skin Types
Not all skin reacts to the sun in the same way. To help you protect yourself effectively, Sun Day uses the Fitzpatrick Scale, a scientific classification that describes how different skin types respond to ultraviolet (UV) radiation.
The Fitzpatrick Scale
| Type I | Always burns, never tans (very fair skin). |
| Type II | Usually burns, tans minimally (fair skin). |
| Type III | Sometimes mild burn, tans uniformly (medium skin). |
| Type IV | Burns minimally, always tans well (olive skin). |
| Type V | Very rarely burns, tans very easily (dark brown skin). |
| Type VI | Never burns, deeply pigmented (black skin). |
How the UV Index Changes the Rules
A UV index of 3 might be safe for Type IV skin for 45 minutes, while Type I skin could burn in less than 15. Sun Day calculates your "Time to Burn" and "Vitamin D Synthesis" specifically for your type.
Protect Your Skin
Download Sun Day and get personalized alerts for your skin type.