Sunmaxxing turns tanning into a science. Live UV, your daily Tan Window, SPF coaching, and a personal burn countdown built around your skin type. Get the perfect glow — without the burn.
Requires iOS 17.0 or later. No account needed.
Dermatology-grounded tools to plan, time, and protect every minute in the sun.
Sunmaxxing detects the exact minutes the sun angle is above 35° — the dermatological threshold where you actually tan. Inside the window: tan. Outside it: save your skin.
A countdown built around YOUR Fitzpatrick skin type and YOUR SPF. Time the front, flip, time the back. No more guessing when you've had enough sun.
Pick your SPF; Sunmaxxing instantly recalculates your safe burn time. Smart reminders to reapply every 2 hours so your protection never lapses.
Real-time UV at your exact location, refreshed every 10 minutes via WeatherKit, with hourly forecasts so you can plan around the peaks.
Per-day UV peaks, temperatures, and conditions for the week ahead. Know which days are made for the beach — and which to skip.
Daily selfies stitched into a visual tan-progression timeline. Watch your glow build week over week — and share your progress with one tap.
A 15-minute heads-up before your Tan Window opens. Never miss the peak — and never get caught out at high noon.
Over 20 milestones across sun sessions, streaks, and tan progression. Earn every glow-up as you build a sun-safe habit.
Available worldwide in English, French, German, Spanish, Italian, Japanese, Korean, Chinese, and 25+ more languages.
A warm, focused interface that puts your safe burn time front and center.
Every burn-time, Tan Window, and UV reading in Sunmaxxing is the output of a calibrated model — not a guess from a generic weather feed. Built on WHO UV guidelines, AAD SPF standards, NOAA solar math, and the Fitzpatrick skin-type framework.
Sunmaxxing follows WHO UV guidelines, AAD SPF recommendations, and Holick’s Rule for vitamin D synthesis. The math is open. The results are personalized.
Beach-goers chasing the perfect summer tan
Vitamin D seekers tracking daily exposure
Outdoor athletes managing burn risk on long days
Fair-skinned people trying not to burn at high noon
The Tan Window is the time range each day when the sun is high enough — above 35° altitude — for UVB rays to actually trigger melanin production in your skin. Outside the window, you mostly get UVA (which ages skin and burns) with very little tanning benefit. Sunmaxxing calculates your local Tan Window every day using NOAA solar position algorithms, so you know exactly when to be outside.
Sunmaxxing combines your Fitzpatrick skin type (which sets your Minimal Erythemal Dose, or MED), live UV index from WeatherKit, cloud cover, sun altitude, altitude boost, surface reflection (snow, sand, grass), and your SPF level into a single personalized burn-time estimate. The model follows WHO UV guidelines, AAD SPF recommendations, and dermatology consensus on real-world SPF behavior.
Sunmaxxing needs internet for live UV updates and the 7-day forecast. Once you've granted location permission and pulled fresh weather, the core math — Tan Window, sun position, burn timer — runs entirely on-device using cached data and NOAA solar algorithms.
During onboarding, Sunmaxxing walks you through a short questionnaire (eye color, hair color, freckles, burn response) that maps to one of six Fitzpatrick skin types — from I (very fair, always burns) to VI (deeply pigmented, never burns). You can also pick directly from a visual chart. Your skin type drives every burn-time calculation in the app.
No. Sunmaxxing is for informational and lifestyle use only. The burn-time math is based on dermatology research and WHO guidelines, but it is not a substitute for medical advice. If you have a history of skin cancer, photosensitive conditions, or are on medication that affects UV sensitivity, please consult a healthcare professional.
No. Your location, skin type, and tan journal stay on your device. Sunmaxxing does not sell your data and does not track you across apps. The only data we send off-device is your coordinates to fetch local weather and UV — and that request goes directly to Apple's WeatherKit servers.
Personalize your skin type and SPF in under 60 seconds. Get your first Tan Window forecast for today, instantly.
For informational purposes only. Sunmaxxing does not provide medical advice. Consult a healthcare professional about your sun exposure plan, especially if you have a history of skin cancer or photosensitive conditions.