UV Exposure Calculator

Calculate safe sun exposure time based on UV index, skin type, elevation, and whether sunscreen is applied. Prevent sunburn on exposed ridgelines.

Results

Visualization

How It Works

UV intensity increases 4% per 1,000 feet of elevation. At 10,000 ft, you get 40% more UV than at sea level. Snow reflects 80% of UV, water 10%. The UV index peaks between 10 AM and 2 PM. SPF 30 blocks 97% of UVB; SPF 50 blocks 98%. Reapply every 2 hours or after sweating/swimming. A wide-brim hat and sun-protective clothing are more reliable than sunscreen alone.