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Estimate how risky today’s UV exposure might be for your skin based on UV index, time outdoors, protection, and sensitivity.
Ultraviolet (UV) radiation from the sun is the primary cause of skin cancer, responsible for approximately 90% of non-melanoma skin cancers and 86% of melanomas. Understanding your daily UV exposure helps you take proactive steps to protect your skin and reduce long-term cancer risk.
This calculator combines today's UV index with your time outdoors, protection habits, and skin sensitivity to give you a daily risk score. While a single day's exposure won't cause cancer, cumulative damage over years determines your lifetime risk.
UV exposure contributes to three main types of skin cancer:
The most common skin cancer, accounting for about 80% of cases. BCC rarely spreads to other parts of the body but can cause significant local damage if untreated. Usually appears as a pearly bump, flat scar-like patch, or sore that doesn't heal.
The second most common type, responsible for about 20% of cases. SCC can spread if not treated but is usually curable when caught early. Often appears as a firm red nodule, scaly patch, or sore that heals and reopens.
Less common but most dangerous. Melanoma can spread quickly to other organs and can be fatal. Usually appears as a new mole or changes in an existing mole. Early detection is critical for survival.
UV radiation damages skin cells in several ways:
Your individual risk depends on several factors:
UV radiation intensity varies dramatically throughout the day:
If possible, schedule outdoor activities for early morning or late afternoon. When midday exposure is unavoidable, maximize protection.
Different protection methods provide different levels of UV reduction:
Combining multiple methods (layered protection) provides the best defense.
Skin cancer develops over years of accumulated UV damage:
Think of UV protection like saving for retirement: small daily contributions add up to significant long-term results.
No. The score reflects relative risk for that specific day. Skin cancer risk builds over many years of cumulative exposure. A high score on one day is a signal to improve protection, not a cancer diagnosis. Consistently keeping daily risk lower over time helps reduce your lifetime risk.
Not necessarily. Even moderate UV contributes to cumulative skin damage and photoaging. UVA rays, which cause aging and contribute to skin cancer, remain relatively constant throughout daylight hours. Many dermatologists recommend daily SPF on exposed areas (especially face) regardless of season or weather.
No. A tan is actually skin damage. When your skin tans, it's producing more melanin in response to UV damage—a protective mechanism against further harm. Any color change from UV exposure indicates DNA damage has occurred. There's no such thing as a "safe" or "healthy" tan.
Yes. While sunburn is a major risk factor, non-burning UV exposure also causes cumulative DNA damage. People with darker skin who rarely burn can still develop skin cancer, and it's often diagnosed later (at more advanced stages) because people don't expect it.
No. Tanning beds are actually more dangerous. They emit concentrated UVA rays (2-3× stronger than midday sun) and are classified as carcinogenic by the WHO. Using tanning beds before age 35 increases melanoma risk by 75%. Avoid them entirely.
Do monthly self-exams to learn your moles and spots. See a dermatologist annually for a full-body check if you have risk factors (fair skin, many moles, family history, history of sunburns). More frequent checks may be recommended if you've had abnormal moles or skin cancer.
Standard window glass blocks most UVB (the burning rays) but allows most UVA (aging/cancer rays) through. You won't burn through a car window, but you'll still get UVA damage. This is why truck drivers often show more aging on their window-side face. Consider UV-blocking window film for cars/homes.
When your shadow is shorter than your height, UV is strong enough to cause damage in a relatively short time. When your shadow is longer than your height (early morning, late afternoon), UV is lower. This is a simple way to gauge UV intensity without checking an app.