- UPF 40 blocks 97.5% of UV; UPF 50 blocks 98%. Both are excellent, but UPF 40 lets through 2.5% versus 2.0%, so about 25% more UV reaches your skin.
- The gap compounds. That small daily difference adds up over years of wear, especially if you're outdoors often or live in a high-UV area.
- A rating can fade, faster on lower-quality fabric. Washing, stretching, and wear lower a fabric's protection over time, so starting at UPF 50+ leaves more margin.
- The '+' means more than 98%. UPF 50+ is the highest UV protection recognized in fabric, tested to exceed the standard UPF 50 mark.
You're holding two clothing tags, one UPF 40 and one UPF 50. The shirts look the same, and they might even feel the same on. So is it worth caring about the difference? On any single day, barely. Over years of wear, more than you'd think. Here's what the numbers mean, and why that small gap is worth paying attention to.
What Do UPF Ratings Mean?
UPF, or Ultraviolet Protection Factor, measures how much UV a fabric lets reach your skin, both UVA and UVB:
| UPF Rating | % of UV Blocked | % of UV Let Through | Protection Level |
|---|---|---|---|
| UPF 30 | 96.7% | 3.3% (1/30) | Very Good |
| UPF 40 | 97.5% | 2.5% (1/40) | Excellent |
| UPF 50 | 98.0% | 2.0% (1/50) | Excellent |
| UPF 50+ | At least 98% | 2% or less | Excellent (maximum) |
The blocked percentages look almost identical, but the number that matters is what gets through: UPF 40 lets through 2.5% of UV and UPF 50 lets through 2.0%, so UPF 40 allows about 25% more UV to reach your skin. The 97.5% versus 98% sounds tiny, but what gets through is what your skin actually feels, and over time that extra margin adds up.
Is UPF 40 Good Enough?
For everyday protection, yes. UPF 40 clothing blocks 97.5% of UV, which is genuinely excellent and just below UPF 50's 98%. If a UPF 40 piece is what you have, wear it with confidence.
The case for going higher is about the long game. Wear the same shirt for several years, and that extra bit of daily UV exposure can mean more cumulative damage over the years, especially if you're outdoors often or live somewhere sunny.
Why Choose UPF 50 Over UPF 40?
Choosing UPF 50 really means reaching for the top of the scale, where the strongest pieces are labeled UPF 50+. Two things make it worth choosing over UPF 40. First, margin. Fabrics lose a little protection to washing, stretching, and wear, so starting at UPF 50+ leaves more room before a piece drops below the protection you wanted.
Second, it costs you nothing. If a UPF 50+ shirt can be just as comfortable as regular clothing, there's little reason not to take the higher protection, which is why many dermatologists recommend UPF 50+ when you can get it. Over the years, a small daily difference protects your skin's long-term health, easing the visible signs of aging and lowering your risk of skin damage.
What Does the '+' in UPF 50+ Mean?
The 'plus' means the fabric tested beyond the standard UPF 50 mark. Where UPF 50 blocks 98% of UV, UPF 50+ blocks more than 98%, the highest level of UV protection currently recognized in textiles. You'll usually find it on apparel designed for extended sun exposure.
How UPF Clothing Compares to Sunscreen
Sunscreen works well, but it asks a lot of you: apply it generously, reapply every two hours, and more often when you sweat or swim. It's also easy to miss spots or use too little. That's a lot of effort for skin a shirt could simply cover.
UPF clothing makes it simpler:
- It doesn't wash off or wear away with sweat
- It's broad-spectrum by default, covering both UVA (the aging ray) and UVB (the burning ray)
- It gives even, all-over coverage to the spots sunscreen often misses, like your back, shoulders, and arms
- It protects the whole time you wear it, with nothing to reapply
We get it: sun-protective clothing used to mean stiff, scratchy, sweat-trapping fabric you couldn't wait to peel off. We built Essuntials® to put that to rest: soft, lightweight, breathable pieces that feel like your favorite tee, with UPF 50+ built in. Each shirt blocks at least 98% of UV and is independently lab-tested and verified to hold that protection through at least 40 washes, so one piece covers you for years and leaves far less sunscreen to buy, apply, and reapply.
Why the Difference Between UPF 40 and UPF 50 Matters
On paper the gap is half a percent. Over years of daily wear, it's the difference between more sun damage, like spots and wrinkles, and less of it, which means healthier skin over time. Since up to 90% of visible aging comes from UV exposure, choosing a higher rating helps preserve both the health and the look of your skin, especially if you're outdoors a lot or live in a high UV Index area.
Frequently Asked Questions About UPF 40 and UPF 50
Here are answers to some of the most common questions about UPF 40 and UPF 50.
Is UPF 40 enough for everyday sun protection?
Yes. UPF 40 blocks 97.5% of UV, which is excellent for daily wear. The case for UPF 50+ is the long game: a little more protection each day adds up over years of sun.
How much more does UPF 50 block than UPF 40?
UPF 40 lets through 2.5% of UV and UPF 50 lets through 2.0%, so UPF 40 allows about 25% more UV to reach your skin. The 'blocked' numbers look almost identical (97.5% versus 98%), but the amount getting through is what counts.
What does the '+' in UPF 50+ mean?
It means the fabric tested beyond the UPF 50 mark, blocking more than 98% of UV. It's the highest UV-protection label recognized in textiles.
Does a UPF rating last forever?
No. Washing, stretching, and everyday wear can lower a fabric's UPF over time, which is one reason to start at UPF 50+. Quality matters too: protection built into the fibers lasts far longer than a surface coating, which is why Essuntials is independently lab-tested and verified to hold UPF 50+ through at least 40 washes.
Do I still need sunscreen if I wear UPF 50+ clothing?
Yes, on the skin your clothing doesn't cover, like your face, neck, and hands. UPF clothing handles everything underneath it, so you need far less sunscreen overall.
The Essential Takeaway
UPF 40 is great protection, but UPF 50+ is the gold standard: the highest defense and the most peace of mind. It's not only about what gets through your shirt today, but what that adds up to for your skin over the years.
The best part is you don't have to trade comfort for it. Choosing UPF 50+ clothing that's soft, effective, and easy to wear every day, like Essuntials, is what real sun protection comes down to: something that works, that you'll actually wear, and that lasts. The best sun protection is the kind you can live in.
Content Disclaimer: This website offers general information about health and related subjects. All content and media on the Essuntials® website are published online for informational and educational purposes only. We do not claim ownership over any 3rd-party content used, which belongs to its respective owners. It is not a substitute for professional medical advice and should not be relied on as health or personal advice. For any medical concerns, please seek professional medical advice.
