Calculate the theoretical UV index (UVI) for your exact location and time, estimate UV on skin-facing angles like the face and arms, and plan sun protection with built-in SPF and PPD sunscreen calculators. Includes a free home screen UV widget, daily and monthly UV index forecasts, cloud-condition toggles, and full offline support. All core features are free.

Beyond sunburn and skin cancer, UV exposure and other actinic damage (Visible and Infrared) account for roughly 80% of visible skin aging. Most people underestimate their daily UV exposure because the apps and weather services they rely on have two problems that this app was built to solve.

First, most UV index apps pull measured readings from sources like NOAA that are typically delayed by an hour or more. The UV index you see may already reflect conditions that have changed. This app calculates a theoretical UV index based on your coordinates, time of day, and atmospheric path, so the estimate updates instantly with the sun's position rather than waiting for the next delayed data refresh.

Second, standard UV readings measure a flat horizontal surface. That is not how your skin faces the sun. Your face, neck, shoulders, and arms are tilted toward the sun at angles that can receive significantly more UV than a horizontal reading suggests. This app applies a tilt correction to estimate UV on skin-facing angles, giving you a more cautious worst-case UV index estimate.

The calculation assumes clear sky by default to produce the highest theoretical UV index for that moment. Optional cloud-condition toggles are available in the app.

Built for skincare routines, anti-aging skin protection, outdoor sun safety, travel, and anyone who wants an immediate UV index estimate that accounts for how skin actually faces the sun.

Why people use this app

- Calculate the theoretical UV index and UVI instantly for any location, no waiting for delayed readings
- Estimate UV on tilted skin-facing surfaces like the face, neck, and arms
- Reduce UV-driven skin aging and actinic damage with better daily UV awareness
- Use the free home screen UV widget for a quick UVI check without opening the app
- View daily and monthly UV index forecasts, a UVI of 3 or more requires protection
- Plan sunscreen use with the SPF calculator and PPD calculator
- Use all features offline with cached data
- Adjust UV estimates for cloud conditions

What makes it different

Other UV index apps show delayed horizontal-surface readings. This app gives you an instant theoretical UV estimate corrected for the angle skin actually faces the sun. No sensor delay. No horizontal-only limitation. A worst-case estimate you can act on.

Useful for

- Daily UV index and UVI checks
- Reducing premature skin aging from UV and actinic damage
- Sun protection and sunscreen planning when UV is 3 or higher
- Skincare and anti-aging users tracking UV on the face, neck, and arms
- Outdoor walks, hiking, cycling, beach days, sports, and travel
- Comparing current UV with daily and monthly forecast levels
- Deciding when to apply or reapply sunscreen

Included tools

- Theoretical UV index / UVI calculator with surface angle correction
- Free UV widget for home screen with cached GPS
- Daily UV index forecast
- Monthly UV index forecast
- SPF calculator
- PPD calculator
- Full offline support
- Cloud-condition toggles

Important note

The UV index, SPF, and PPD calculations are educational tools providing theoretical estimates. They are not a substitute for measured UV data, professional sunscreen testing, medical advice, or regulatory compliance. Always follow your sunscreen product label and consult a dermatologist for skin health concerns.