PA+++ is a sunscreen rating that tells you how much protection a product offers against UVA rays, the type of ultraviolet radiation most responsible for skin aging and long-term damage. Specifically, PA+++ means the sunscreen blocks 8 to 16 times the UVA radiation your bare skin would absorb. The system was developed by the Japan Cosmetic Industry Association and is now standard on sunscreen labels across most Asian markets.
How the PA Rating System Works
PA stands for “Protection Grade of UVA.” It’s based on a testing method called Persistent Pigment Darkening (PPD), which exposes skin to UVA radiation and measures how long it takes for visible, lasting darkening to appear. That result gets converted into a simple grade using plus signs, where more plus signs mean stronger protection.
The four tiers break down like this:
- PA+: PPD of 2 to 4 (some UVA protection)
- PA++: PPD of 4 to 8 (moderate UVA protection)
- PA+++: PPD of 8 to 16 (high UVA protection)
- PA++++: PPD of 16 or higher (very high UVA protection)
So a PA+++ sunscreen means your skin takes 8 to 16 times longer to darken under UVA exposure than it would unprotected. PA++++ is the highest grade available and was added as a fourth tier after the original three-tier system proved insufficient to distinguish among the most protective formulas on the market.
Why UVA Protection Matters Separately
Most people know SPF, but SPF only measures protection against UVB rays. UVB is the type that causes sunburn and directly damages DNA in skin cells. UVA operates differently. It penetrates deeper into the skin, doesn’t cause obvious burning, and does its damage through a more indirect route: it generates reactive oxygen molecules inside cells that then harm DNA, cell membranes, and collagen.
Here’s the key detail that makes UVA worth paying attention to: sunlight at ground level contains more than 20 times as much UVA energy as UVB energy. So even though UVA is less potent than UVB on a ray-for-ray basis, the sheer volume of it means it contributes meaningfully to skin cancer risk and is the primary driver of photoaging, including wrinkles, dark spots, and loss of elasticity. A high SPF with weak UVA protection leaves a significant gap.
PA+++ vs. Broad Spectrum Labeling
If you’re in the United States, you won’t typically see PA ratings on domestic sunscreen brands. Instead, the FDA uses “broad spectrum” labeling, which indicates a product protects against both UVA and UVB rays. The catch is that “broad spectrum” is a pass/fail designation. It tells you UVA protection exists but doesn’t tell you how much. Two sunscreens can both be labeled broad spectrum while offering very different levels of UVA defense.
The PA system is more specific because it grades UVA protection into distinct tiers. A product can carry a broad spectrum label without a PA rating, and vice versa. If you’re comparing sunscreens and one lists PA+++, you have a clearer picture of its UVA performance than you would from a broad spectrum claim alone. This is one reason many skincare-conscious consumers seek out Asian sunscreens or international brands that include PA ratings on their packaging.
Getting the Protection on the Label
Both SPF and PA ratings are tested in a lab at a standardized application thickness of 2 milligrams per square centimeter of skin. That’s a specific, measurable amount, and most people apply far less than that in real life. If you use half the tested amount, your actual protection drops dramatically.
For your face alone, a good rule of thumb is about two finger-lengths of sunscreen, meaning a stripe of product along your index and middle fingers from base to tip. This approximates the 2 mg/cm² standard and gives you something close to the PA+++ protection printed on the bottle. Applying less than that means your real-world protection is lower than the rating suggests, no matter what the label says.
Choosing Between PA+++ and PA++++
For everyday use with limited sun exposure, PA+++ provides strong UVA protection. It’s a meaningful step above PA++ and covers most daily scenarios like commuting, running errands, or working near windows. PA++++ offers the highest tier of protection and is worth choosing if you spend extended time outdoors, have a history of sun damage, or are particularly concerned about photoaging. The difference between the two tiers can be substantial: PA+++ tops out at a PPD of 16, while PA++++ has no upper limit, so some PA++++ products may offer significantly more UVA defense than the minimum threshold suggests.
When shopping, look at both the SPF number and the PA rating together. A sunscreen with SPF 50 but only PA++ has strong burn protection with moderate UVA defense. A sunscreen with SPF 30 and PA++++ offers less burn protection but superior UVA shielding. The best daily sunscreens pair a high SPF with PA+++ or PA++++, covering both types of ultraviolet damage.