SPF describes protection against sunburn, caused mainly by UVB. PA describes UVA protection. Read the two together when comparing sunscreens: a high SPF does not tell you the PA grade, and PA++++ does not mean that a sunscreen lasts all day.
This guide explains the difference between SPF and PA, what the plus signs mean, and how to use those ratings when choosing sunscreen or makeup with SPF.
What does SPF mean on sunscreen?
SPF stands for Sun Protection Factor. It compares the amount of UV exposure needed to cause sunburn on protected skin with the amount needed on unprotected skin under test conditions. It primarily reflects UVB protection.
SPF is not a safe-time multiplier. SPF 30 does not mean you can stay in the sun 30 times longer. The FDA explains that exposure depends on the intensity of sunlight, as well as factors such as how much sunscreen you apply. A higher number does not remove the need to reapply.
The American Academy of Dermatology recommends SPF 30 or higher. No sunscreen filters every UV ray, so combine sunscreen with shade and protective clothing.
What does PA++++ mean?
PA stands for Protection Grade of UVA. The Japanese PA system groups measured UVA protection factors into four grades. UVA contributes to skin ageing and skin cancer; it deserves attention alongside UVB protection.
| Label | UVA protection factor (UVA-PF) |
|---|---|
| PA+ | 2 to less than 4 |
| PA++ | 4 to less than 8 |
| PA+++ | 8 to less than 16 |
| PA++++ | 16 or higher |
These ranges come from the Japan Cosmetic Industry Association's PA classification. PA++++ is the highest category in this four-grade system, but it is a category, not an exact UVA-PF. Two products with PA++++ may therefore have different measured UVA protection factors.
The plus signs do not specify hours of protection. They also do not measure water resistance or protection from visible light.
SPF, PA and broad spectrum: what is the difference?
Use each label for the question it answers:
- SPF: how much protection against sunburn was measured?
- PA: which UVA protection category does the formula meet?
- Broad spectrum: does the sunscreen provide both UVA and UVB protection?
- Water resistance: what does the label say about use during swimming or sweating?
The AAD's sunscreen label guide recommends broad-spectrum protection, SPF 30 or higher, and water resistance. Check the directions on the product you buy; “water resistant” does not mean waterproof.
Can you add the SPF in sunscreen and makeup?
No. SPF 30 sunscreen plus SPF 15 foundation does not become SPF 45. Nor can you assume your routine automatically delivers the highest number on any one bottle: the amount applied and the evenness of coverage matter.
Johns Hopkins Medicine notes that people generally use too little makeup to achieve its labelled SPF. Use sunscreen as your main sun-protection step rather than relying on a light layer of foundation or setting powder. Follow the sunscreen's application directions and allow it to settle before applying makeup gently.
Do mineral, chemical and hybrid sunscreens use different ratings?
The filter type and the protection rating answer different questions. Mineral sunscreens use zinc oxide or titanium dioxide; chemical sunscreens use other UV filters; hybrid formulas combine both types.
It is misleading to say mineral sunscreens only reflect UV while chemical sunscreens absorb it. Both absorb UV; mineral filters also reflect some. Compare the finished product's labelled protection and how comfortably it fits your routine, rather than judging performance from the filter category alone.
Reading the label on Beyond Sun Protection
Crystal Tomato® Beyond Sun Protection sunscreen is labelled SPF79+ PA++++. The SPF refers to its measured sunburn protection, while PA++++ places its UVA protection in the highest PA category. Neither rating is a promise of all-day protection from one application.
You can review the brand's Beyond Sun Protection testing summary for product-specific information. For help comparing texture and suitability, read our guide to choosing a face sunscreen for your skin type.
Apply and reapply: the ratings are only part of the routine
Apply sunscreen generously and evenly to exposed skin according to its directions. When outdoors, reapply at least every two hours, and promptly after swimming or sweating; follow the label's instructions after towel drying. High SPF and PA++++ do not extend this interval.
Plan protection around your actual day: commuting, lunch outdoors, swimming and time near sunny windows can involve different exposure. Cloudy weather is not a reason to skip protection outdoors. Keep sunscreen accessible and use shade, a hat and protective clothing as well.
Frequently asked questions about SPF and PA
Is PA++++ the same as SPF 50?
No. PA++++ is a UVA protection category; SPF 50 is a sunburn-protection rating. Look for information about both UVA and UVB protection.
Does PA++++ protect against blue light?
PA measures UVA protection, not visible or blue light. Do not infer a visible-light protection claim from the plus signs; that needs separate supporting evidence.
Does higher SPF mean I can apply less?
No. Follow the amount and application directions on the label. A higher rating does not make a thin or patchy application equivalent to the tested application.
Can I skip reapplication if my makeup contains SPF?
No. Makeup with SPF does not cancel your sunscreen's reapplication directions. Plan a practical way to reapply when you spend time outdoors.
