☀️ Sunbathing Calculator
Estimate roughly how long you can sunbathe before your skin’s natural protection is used up, based on skin type, UV index, and sunscreen.
Estimating safe sun exposure
How long skin can be in the sun before burning depends on skin type (its natural melanin protection), the UV index (a measure of how strong the sun’s UV radiation is), and any sunscreen applied. This calculator combines those factors into a rough estimate of safe exposure time.
How the estimate is calculated
Each Fitzpatrick skin type has a different baseline time to burn under moderate UV. That baseline is scaled inversely with the current UV index (higher UV means less time), and then multiplied by your sunscreen’s SPF factor, capped at a realistic maximum, to estimate protected exposure time.
This is a general educational estimate, not medical advice. Sunscreen should be reapplied every two hours or after swimming/sweating regardless of SPF, and factors like altitude, reflection off water or snow, cloud cover, and time of day also affect real UV exposure. When in doubt, use broad-spectrum sunscreen, seek shade during peak hours, and consult a dermatologist for personal skin care guidance.