Climate & Environment

UV Index Calculator

Free UV index calculator. Estimate safe sun exposure time, sunburn risk, and SPF recommendations based on UV index and your Fitzpatrick skin type.

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Calculate Your Safe Sun Exposure Time

The UV Index measures the strength of ultraviolet radiation from the sun. Our calculator uses the WHO/WMO standard UV index scale and Fitzpatrick skin type classification to estimate how long you can safely stay in the sun without protection, and what SPF level you need.

What Is the UV Index?

The UV Index is an international standard measurement developed by the WHO and WMO. It ranges from 0 (nighttime) to 11+ (extreme). The scale is linear - UV Index 10 is twice as intense as UV Index 5. Higher values mean faster potential for sunburn and skin damage.

Time to Burn Formula

t = (MED × 16.67) / UV Index

Why Use a UV Index Calculator?

Prevent Sunburn

Know exactly how long you can stay outside before risking skin damage.

Optimize Vitamin D

Get enough sun for vitamin D production without overexposure.

Choose Right SPF

Select appropriate sunscreen protection for current UV conditions.

How to Use This Calculator

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Common Applications

Beach Days

Plan sun exposure at the beach where reflection can increase UV by 50%.

Skiing & Hiking

Account for altitude and snow reflection in mountain environments.

Outdoor Sports

Athletes can time training to avoid peak UV hours.

Travel Planning

Prepare for different UV levels in tropical or high-altitude destinations.

Frequently Asked Questions

At UV Index 0-2 (Low), most people can safely stay outside with minimal protection. At UV Index 3+ (Moderate and above), sunscreen, hats, and protective clothing are recommended, especially for fair-skinned individuals.