You’ve probably seen SPF 50 and PA++++ on sunscreen labels, but let’s be honest—those numbers don’t explain much by themselves. If you’re serious about protecting your skin, especially from long-term damage, you need to understand what each one does.Let’s walk through both, clearly and without fluff.Scroll ahead to learn the meaning of SPF, PA, and squash different myths surrounding these terms.What SPF Actually CoversSPF stands for Sun Protection Factor, and it measures how well your SPF 50 Sunscreen defends against UVB rays – responsible for sunburn and surface-level irritation. For the uninitiated, UVB rays peak from mid-morning through late afternoon and can bounce off surfaces such as water and pavement.SPF 30 filters out roughly 97% of UVB rays, while SPF 50 offers about 98% protection. That single percent might seem minor, but it can make a real difference during prolonged sun exposure. SPF only handles part of the UV spectrum, it won’t stop the deeper damage. That’s where PA comes in.What the PA Rating CoversPA refers to the Protection Grade of UVA, indicating how well a product shields your skin from UVA rays. These radiation penetrate deeper than UVB and contribute to long-term damage, resulting in accelerated skin ageing dark spots, and dwindling Collagen over time.Also, UVA rays are sneaky. They’re out year-round, even on cloudy days. They pass through windows, too—meaning you’re exposed even when you’re inside or driving.The PA system, developed in Japan, uses “+” signs to show strength:- PA+ offers some UVA protection- PA++ gives moderate coverage- PA+++ means strong defense- PA++++ is the highest you’ll find in most non-prescription sunscreensIf your concerns include uneven skin tone, pigmentation, or early signs of aging, don’t skip this rating.Related Article: Guide on how to read sunscreen labelWhy You Need SPF and PA BothSPF and PA measure different types of protection. Think of SPF as your surface-level defense and PA as the deeper layer of protection. Your skin needs both, especially if you’re outdoors often or live somewhere with high UV levels.Also, relying on SPF alone leaves your skin exposed to photoaging—even if you’re not getting sunburned.So, How Do You Know If a Sunscreen Covers Both?Start by checking for “broad spectrum” on the label. That term means it offers protection from both UVA and UVB rays.Next, confirm that the product actually lists both SPF and PA ratings. If you only see SPF, it’s probably not giving you full UVA coverage.Choose a sunscreen with at least SPF 30 and a PA rating of +++ or higher. For extended sun exposure or concerns like pigmentation, opt for SPF 50 and the maximum PA protection.Common Myths About SPF and PA RatingsMyth 1: Higher SPF means longer-lasting protectionNot exactly. SPF tells you what percentage of UVB is blocked—not how long the product lasts. You still need to reapply it every 2-3 hours when you’re outdoors.Myth 2: SPF 50 covers everythingIt covers UVB well, but without PA, it won’t protect you from UVA-related aging or discoloration.Myth 3: PA++++ sunscreen stays on all dayNo sunscreen lasts forever. Sweat, water, and heat all wear it down. You still need to reapply it regularly.Myth 4: You’re safe indoors without sunscreenUVA rays easily pass through glass. If you sit near windows or drive often, you still need a layer of protection.Myth 5: SPF 100 means twice the strength of SPF 50Nope. SPF 100 blocks about 99% of UVB rays, compared to approximately 98% with SPF 50. That’s only a 1% difference.Related Article: Myths vs Facts of SunscreenHere’s How to Actually Use Sunscreen CorrectlySunscreen only works if you use the right amount—and apply it properly.1. Use enough: A pea-sized amount won’t cut it. 2 fingers’ worth of sunscreen to cover both your face and neck. For your whole body, you’ll need around 30ml (roughly one shot glass).2. Apply to dry skin: Make sure your skin is clean and dry before putting it on. Let it absorb before layering anything else.3. Don’t skip spots: Ears, eyelids, hairline, back of the neck—these often get missed.4. Reapply often: Every 2 to 3 hours if you’re outside. More often if you’re swimming or sweating.5. Wear it daily: Even if it’s cloudy. Even if you’re just commuting.Also, if you have oily or acne-prone skin, look for a sunscreen for oily skin or a matte sunscreen. You want protection that won’t clog pores or feel greasy—especially in hot, humid weather.Related Article: 1. Choosing Sunscreen between SPF 30 vs 50 vs 702. Common Sunscreen mistakesBottom Line: SPF Handles the Burn, PA Handles the Long-TermSPF protects against UVB. PA handles UVA. Both are critical.So when you’re picking a sunscreen, don’t just go by the highest SPF you can find. Consider the whole picture and ensure it addresses both sides.Apply it right, reapply it often, and make it part of your routine. That’s how you protect your skin now and avoid issues later.