Vitamin D Calculator
Estimate vitamin D production from sun exposure.
See how it works
Watch a quick simulation of this tool in action — no file needed.
How to use Vitamin D Calculator
Follow these steps — everything happens instantly in your browser.
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Step 1. Enter sun exposure time in minutes.
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Step 2. Enter the percentage of body area exposed.
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Step 3. Pick your skin type (Fitzpatrick I–VI).
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Step 4. Pick the UV conditions (season, time of day, indoor/outdoor).
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Step 5. Read estimated IU produced plus safe exposure and burn thresholds.
Why use this tool
Private by design
All processing happens locally in your browser. Open DevTools → Network and you'll see zero file uploads. Ever.
Instant
No upload wait, no queue, no server round-trip. Results appear the moment you drop a file.
Free & unlimited
No accounts, no watermarks, no daily caps. Use it as many times as you like, forever.
Works everywhere
Desktop, tablet or phone — every tool is responsive and installable as a PWA for offline use.
Frequently asked questions
Everything you might want to know about vitamin d calculator.
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