What SPF and PA ratings mean on a Korean sunscreen label

Pick up a Korean sunscreen and you’ll usually find two ratings on the front: an SPF number, and a row of plus signs after the letters PA. US sunscreens show the SPF but not the PA, so that second one throws a lot of people. Both are telling you something worth knowing, and they’re measuring two different kinds of ultraviolet.

Two numbers, two kinds of UV

Sunlight reaches your skin as two bands of ultraviolet that matter here. UVB is the shorter, stronger band — it’s what reddens and burns skin, and it does most of its damage at the surface. UVA is the longer band. It’s weaker at burning but reaches deeper into the skin, and it’s the one tied to aging, loss of firmness and pigmentation. It’s also steadier through the day than UVB and passes through glass, so it reaches you in the car and through a window, on ordinary days as much as at the beach. A sunscreen that handled UVB alone would leave the aging rays to get on with it. The two ratings on a Korean bottle exist because each number covers one of these bands.

What the SPF number means

SPF — sun protection factor — is the UVB rating. It’s a measure of how much longer protected skin can take UVB before it burns, set against bare skin. The jump from a middling number to a high one is smaller than it looks: SPF 30 filters roughly 97% of UVB, and SPF 50 around 98%. Past that the gains shrink to almost nothing, which is why the very high numbers on US shelves oversell themselves. Some countries cap what a label may claim at SPF 50+; the US does not, so a bottle can claim SPF 70 or SPF 100, and the FDA has proposed — but not finalised — capping labels at 60+. Those numbers are real measurements; they just buy you a fraction of a percent over SPF 50 while reading like twice the protection. For daily wear, SPF 30 to 50 applied properly beats SPF 100 applied thinly, every time.

What PA and the plus signs mean

PA is the UVA rating, and it’s where a Korean label parts ways with ours. It grades how well a sunscreen holds off UVA, using a test that measures how long UVA takes to darken the skin — the persistent pigment darkening method. The scale is written in plus signs: PA+ is some UVA protection, PA++ is moderate, PA+++ is high, and PA++++ is the top grade, recognized in 2013. The system was developed by the Japan Cosmetic Industry Association and is now standard across Japanese and Korean sunscreens, which is why it turns up on a Korean bottle and not a US one. More pluses means more of the aging band held off. Under a strong sun, PA+++ or PA++++ is the range to look for.

Why you want both numbers high

The two ratings expose a gap: a high SPF doesn’t promise strong UVA cover. The two are measured separately, and a sunscreen can post a big SPF while doing much less against UVA. That gap is the whole reason the second rating exists — so a high SPF can’t quietly stand in for protection it isn’t giving. On a Korean label the pairing to look for is SPF 50+ alongside PA++++: the most UVB cover the system allows, next to the strongest UVA grade. One high number on its own only covers one band.

Getting the rating you paid for

A rating is a lab result under ideal conditions, and real skin rarely matches the lab. The tests lay down a thick, even film — about two milligrams per square centimetre — and most people apply a fraction of that, which drops the real protection well below the number on the bottle. On the amount, the American Academy of Dermatology is specific: about an ounce — a shot glass — to cover the body, roughly a teaspoon of that for the face and neck, topped up every two hours in the sun and after a swim or a sweat.

Even coverage is easier over a smooth, hydrated base than over dry or flaky skin, where sunscreen can drag and skip. A light hydrating toner after cleansing is an easy way there — a watery layer that leaves the skin comfortable and even, with no film for the sunscreen to slide on. It sinks in fast, so it won’t disturb the SPF that goes on later, and sunscreen laid over settled skin tends to go on in a more even coat.

A light moisturizer is the last layer before sunscreen, so the state it’s in shapes how evenly the SPF sits. Spread over cream that hasn’t sunk in yet, sunscreen can bead and streak instead of covering cleanly — and patchy cover is lost protection, whatever the number claims. Give a gel or lightweight cream a moment to settle, then lay the sunscreen over skin that’s hydrated but no longer tacky. That’s the even coat the rating assumes, and about the closest most of us get to the lab film in a real morning. The number is still a claim even when you apply it well: independent testing has repeatedly found sunscreens that fall short of their labeled SPF, which is another reason not to treat a very high number as a licence to apply less.

The US label, and what’s missing

The US doesn’t use the PA system at all. Here, a sunscreen that passes the FDA’s UVA test earns the words “Broad Spectrum” on the label — that phrase is the US version of a UVA grade, a single pass-or-fail mark where PA gives you a scale of pluses. So the pairing to look for on a US bottle is “Broad Spectrum” next to an SPF number, where on a Korean one it’s PA++++ next to SPF 50+.

That difference cuts in Korea’s favour if you care about UVA. “Broad Spectrum” tells you a product cleared the bar; it doesn’t tell you by how much. PA++++ and PA+ both clear a bar too, but the scale tells you where a product sits on it. If you are choosing between two sunscreens for pigmentation or aging rather than burning, a graded UVA rating is simply more information than a binary one.

There’s a second, larger difference, and it’s the one specific to buying Korean sunscreen in the US. Sunscreen here is regulated as an over-the-counter drug, and what a US sunscreen may contain comes from a short list of permitted UV filters. Several of the filters that give Korean sunscreens their light textures — Uvinul A Plus, Uvinul T150, Tinosorb M, Uvasorb HEB — are not on it. So a Korean sunscreen you buy here is usually an import rather than a US-regulated sunscreen: its SPF and PA come from Korean testing under Korean rules, and the FDA has never assessed either figure.

Plenty of people wear them anyway. The thing to hold in mind is that both numbers are the manufacturer’s tested claim rather than an independently assessed US one. What that means in practice, what the 2026 approval of bemotrizinol changed and what it didn’t, is in our sunscreen guide; the sunscreen category gathers the ones we’ve written about.

What to check on the bottle

• SPF 30 or higher — the AAD’s daily baseline. SPF 50 is a sensible ceiling; past that the gains are marginal and the bigger number mostly sells confidence.
• PA+++ or PA++++ on a Korean label — strong UVA cover. On a US label, look for the words “Broad Spectrum” in its place.
• Look for both — a high SPF with a low or missing UVA rating still lets the aging rays through.
• Enough of it — about a teaspoon for the face and neck, reapplied every two hours outdoors, or the ratings don’t hold up.
• Whether it’s a US-regulated sunscreen or an import — most cult Korean SPFs are the latter; the sunscreen guide above explains what follows from that.

Where this leaves you

So the label is telling you about two different bands of UV — SPF for the one that burns, PA for the one that ages. On a Korean sunscreen you want SPF 50+ PA++++, and then you want to actually wear it every morning, in the quantity the rating was measured at, which is more than most people apply. And no single bottle is the whole job — the AAD treats sunscreen as one layer alongside shade, protective clothing, a wide-brimmed hat and sunglasses. Where sunscreen sits against the where sunscreen goes in a Korean routine. Building the whole thing from scratch, start with the Korean skincare routine and add a hydrating layer underneath.