What sunscreen is best? The criteria that actually matter

Start with the three non-negotiables

Bottom line: any product that meets these three requirements is a reasonable pick. The American Academy of Dermatology asks everyone to use a sunscreen with broad-spectrum (UVA and UVB) protection, an SPF of 30 or higher, and water resistance (AAD sunscreen FAQs).

• Broad-spectrum protection against both UVA and UVB
• SPF 30 or higher
• Water resistant

Chemical versus physical is not the deciding factor. Both types can protect you well if they meet all three criteria.

SPF 30 is the floor, and 50 makes sense for long days

Bottom line: SPF 30 covers daily use, and SPF 50 is worth it for extended time outdoors. SPF 15 filters out about 93% of UVB rays and SPF 30 about 97%, according to the AAD label guide. No sunscreen blocks 100%.

The Skin Cancer Foundation recommends SPF 50 or higher for extended outdoor activity and SPF 30 or higher for daily and incidental protection (Skin Cancer Foundation sunscreen guide).

Be wary of very high numbers. The foundation notes that products with very high SPFs can create a false sense of security, which leads people to stay out longer or skip reapplication.

Read the back label for broad spectrum and water resistance

Bottom line: the SPF number only tells you about UVB, so the broad-spectrum claim is what covers UVA. SPF values primarily indicate UVB protection. Under FDA's broad-spectrum test, a product must show UVA protection proportional to its UVB protection, so higher SPFs must deliver more UVA protection too (FDA questions and answers).

Waterproof is no longer a permitted claim, because sweat and water wash sunscreen off. A water resistant label states whether protection holds for 40 or 80 minutes on wet skin (AAD label guide).

Pick the formula you will actually use

Bottom line: the best formula is the one you'll reapply. The Skin Cancer Foundation takes the same usability-first position, as long as the product is safe, effective, and broad spectrum (Skin Cancer Foundation sunscreen guide).

• Sensitive skin: dermatologists often recommend mineral, or physical, formulas (AAD label guide).
• Visible light and pigmentation: tinted sunscreens with iron oxide, at SPF 30 or higher, help against visible light. Visible light can worsen darkening of the skin, especially for people with darker skin tones (AAD FAQs).
• Babies: avoid sunscreen under 6 months if possible (AAD FAQs).
• Sprays: never spray near the face or mouth, and do not spray into the wind (AAD FAQs).
• Lips: use a lip balm with an SPF of at least 30 (AAD application guide).

For more background, see our sunscreen topic page.

What the evidence can and cannot tell us

Bottom line: we found no systematic review, randomized trial, or head-to-head brand comparison. Every criterion above is guidance or a regulatory definition, not proof that one brand outperforms another.

We did not use dermatologist surveys or brand lists as evidence, since they reflect opinion and marketing reach. The Skin Cancer Foundation cites reductions in squamous cell carcinoma and melanoma risk with daily SPF 15 use, but we could not trace the primary trials behind those figures, so we are not repeating the numbers.

The FDA has proposed capping labeled SPF at 60+, citing meaningful added clinical benefit from broad-spectrum SPF 60 products. That is a proposal, not a final rule (FDA fact sheet).