Estimate the midday sun exposure that produces meaningful vitamin D for your skin type, scaled by the current UV index.
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Fill in the form and press Calculate. You will get your number, an interpretation chip, and a personalized chart pack drawn instantly in your browser.
- Risk spectrum with your position marked
- Reference ranges from the original publication
- Shareable link, nothing stored
Scientific references
The estimate
At UV index 5, producing a useful vitamin D dose takes roughly fifteen minutes for fair skin and up to forty five for dark skin, with forearms and legs exposed. The tool scales that base inversely with the UV index.
Understanding your result
- Under eleven minutes is a short easy exposure
- Eleven to twenty five is moderate
- Above twenty five minutes suggests supplements are the practical route
Why darker skin needs more
Melanin blocks the ultraviolet that starts vitamin D synthesis, which protects against burning but multiplies the time needed by two to three.
Practical notes
Glass blocks synthesis completely, sunscreen reduces it strongly, and winter sun above mid latitudes is too weak regardless of exposure time.