Buying sunscreen comes down to four things: SPF level, the type of UV protection, the formula that works for your skin, and whether it holds up during your activities. SPF 30 is the minimum worth buying for daily use, and most people need a broad-spectrum formula that protects against both types of UV radiation. Beyond that, the best sunscreen is the one you’ll actually wear consistently. Here’s how to read the labels and pick the right one.
What SPF Number to Look For
SPF measures how well a sunscreen blocks UVB rays, the type that causes sunburn. The numbers don’t scale the way you’d expect. SPF 30 blocks 97% of UVB rays, SPF 50 blocks 98%, and SPF 100 blocks 99%. The jump from 30 to 50 is just one percentage point of additional protection, so SPF 30 is the sweet spot for most people. The American Academy of Dermatology recommends SPF 30 as a minimum.
Higher SPF can be worth it if you burn easily, spend long stretches outdoors, or have a history of skin cancer. But no SPF number replaces reapplication. A perfectly applied SPF 30 reapplied every two hours outperforms SPF 50 applied once and forgotten.
Why “Broad Spectrum” Matters
SPF only measures UVB protection. UVA rays penetrate deeper into the skin, contribute to premature aging, and play a role in skin cancer. A sunscreen labeled “broad spectrum” has been tested to confirm it filters both UVA and UVB radiation. If the label doesn’t say broad spectrum, you’re only getting half the protection. Look for those two words on every bottle you pick up.
If you’re shopping outside the U.S., you may see a PA rating system with plus signs (PA+++, PA++++), which grades UVA protection specifically. The more plus signs, the better. The U.S. doesn’t use this system, but imported sunscreens sometimes display it.
Mineral vs. Chemical Sunscreen
Sunscreens use one of two approaches to block UV light, and understanding the difference helps you pick the right formula for your skin.
Mineral sunscreens (also called physical sunscreens) contain zinc oxide, titanium dioxide, or both. These sit on top of your skin and reflect UV rays away, like a shield. They start working immediately on application, tend to be gentler on sensitive skin, and zinc oxide has mild anti-inflammatory properties that can help with redness.
Chemical sunscreens use ingredients like avobenzone, oxybenzone, and octinoxate. These absorb into the skin, soak up UV rays like a sponge, and convert them into heat that dissipates. They tend to apply more smoothly and invisibly, but they need about 15 to 20 minutes after application to become fully effective.
Many modern sunscreens blend both types. Neither category is inherently better. The choice depends on your skin’s needs and your preferences for texture and appearance.
Choosing a Formula for Your Skin Type
If you have acne-prone skin, look for the word “noncomedogenic” on the label, which means the product is designed not to clog pores. Avoid sunscreens with heavy oils like mineral oil, petrolatum, coconut oil, or cocoa butter, all of which can trap bacteria and trigger breakouts. Alcohol-based formulas can also backfire: they strip oils from your skin, which triggers your skin to produce even more oil. Fragrance and added pigments are also common irritants worth skipping.
Mineral sunscreens with zinc oxide are a strong choice for sensitive or acne-prone skin. Ingredients like glycerin, aloe vera, and niacinamide in the formula can help with hydration and redness without aggravating breakouts.
If you have a darker skin tone, mineral sunscreens can leave a noticeable white cast because zinc oxide and titanium dioxide are naturally white powders that sit on the skin’s surface. Tinted mineral formulas solve this problem. Some brands now use micronized particles or sheer-finish technology to reduce the chalky look while still providing full protection. Look for formulas specifically labeled as tinted or sheer if white cast has been an issue for you.
Lotion, Spray, or Stick
Lotion is the most reliable format. You can see exactly how much you’re applying and where you’ve missed spots. For reference, you need about one ounce (a shot glass full) to cover your entire body, and about one teaspoon just for your face. That teaspoon is roughly enough to cover the length of your index and middle fingers laid side by side.
Spray sunscreens are convenient for hard-to-reach areas like your back and for quick touch-ups. But people consistently under-apply them. To use a spray effectively, keep spraying until your skin looks wet and shiny, then rub it in by hand before it dries. Never spray directly onto your face, since the mist can irritate your eyes and nasal passages. Spray it onto your hands first, then apply to your face.
Stick sunscreens work well for small areas like ears, the nose, and around the eyes. They’re portable and mess-free but impractical for full-body coverage.
Understanding Water Resistance Labels
No sunscreen is waterproof. The FDA actually prohibits manufacturers from using the words “waterproof” or “sweatproof” on labels because all sunscreens eventually wash off. What you’ll see instead is “water resistant” followed by either 40 minutes or 80 minutes. That number tells you how long the sunscreen maintained its full SPF protection during standardized water-immersion testing.
If you’re swimming, sweating, or spending time at the beach, look for “water resistant (80 minutes)” on the label. Even then, reapply immediately after toweling off. Water-resistant sunscreen is essential for outdoor activities, but it’s not a set-it-and-forget-it solution.
Reef-Safe Sunscreen
If you’re swimming in the ocean, particularly near coral reefs, certain sunscreen ingredients can harm marine ecosystems. Hawaii passed the first statewide ban on oxybenzone and octinoxate in 2018, and other coastal areas have followed. “Reef safe” generally means the sunscreen uses only mineral filters like zinc oxide and titanium dioxide instead of chemical ones.
Beyond oxybenzone and octinoxate, environmental guides flag several other ingredients to avoid near reefs: octocrylene, homosalate, parabens, triclosan, and nano-sized zinc or titanium particles. If your sunscreen rubs in completely clear and doesn’t explicitly say “non-nano” or “micro-sized,” it likely contains nanoparticles. Mineral sunscreens labeled non-nano are the safest bet for ocean swimming.
Checking Expiration and Storage
Sunscreen is required to remain effective for at least three years from manufacture. Some bottles print an expiration date; if yours doesn’t, write the purchase date on it with a marker. Toss it after three years regardless of how much is left.
Heat and direct sunlight break down the active ingredients faster than time alone. Don’t leave your sunscreen baking on a dashboard or sitting in the open sun at the beach. Keep it in the shade, wrap it in a towel, or toss it in a cooler. If the texture has separated, turned gritty, or the smell has changed noticeably, the formula has degraded and won’t protect you properly.
A Quick Shopping Checklist
- SPF 30 or higher: The baseline for meaningful protection.
- Broad spectrum: Confirms both UVA and UVB coverage.
- Water resistant (40 or 80 minutes): Essential if you’ll sweat or swim.
- Noncomedogenic: Important if you’re prone to breakouts.
- Mineral filters (zinc oxide, titanium dioxide): Best for sensitive skin, ocean swimming, or avoiding chemical filters.
- Tinted or sheer finish: Reduces white cast on darker skin tones.
- Fragrance-free: Reduces irritation risk for all skin types.
You don’t need every item on this list. Pick the features that match your skin, your activities, and where you’ll be wearing it. The most effective sunscreen is the one you’ll reach for every day without dreading the application.