What Is the Difference Between UPF and SPF?

We hear these two terms all the time — UPF and SPF — but what do they really mean, and how are they different? If you've ever wondered whether one is better than the other (or if you even need both), you're not alone. Let's break it down in simple terms.

First things first: SPF is for skin, UPF is for fabric

• SPF (Sun Protection Factor) tells you how well a sunscreen protects your skin against UVB rays, the ones that cause sunburn. For example, SPF 30 means it would take 30 times longer for your skin to burn compared to wearing no sunscreen at all.
• UPF (Ultraviolet Protection Factor), on the other hand, measures how much UV radiation a fabric blocks. Clothing labeled UPF 50+ lets in only about 2% of UV rays — keeping up to 98% off your skin.

So in short: SPF = sunscreen. UPF = clothing. Both are about protection, just applied differently.

Why do you need both?

Relying only on sunscreen can leave gaps. Sunscreen needs to be reapplied every two hours, and it’s easy to miss spots. Meanwhile, not all clothing naturally protects you — for example, a thin cotton shirt might only have a UPF rating of 5. That means while it blocks about 80% of UV rays, the other 20% still reach your skin. By comparison, UPF 50+ fabrics, like those used in NINI’s collections, block up to 98% of UV rays — offering a much higher level of consistent protection.

That’s why the best approach is layering the two. Cover large areas with UPF clothing and use SPF on exposed skin. It’s a team effort.

Want an example of UPF coverage done elegantly? The Long Sleeve Ruffle Dress in Black/Beige delivers full-arm, ankle-length coverage with UPF 50+, so you need less sunscreen underneath.

Does UPF protect against both UVA and UVB?

Yes — and that’s one of the big differences. SPF ratings only measure UVB protection, not UVA. But UPF testing accounts for both UVA and UVB, which means UPF clothing helps defend against the rays that cause both burning and long-term skin aging.

For chic all-day UVA + UVB coverage, try the Sheer Straight Leg Pant in Black/White. They’re breezy enough for summer but tested for UPF 80+ protection.

Do UPF and SPF wear off?

• SPF needs to be reapplied after swimming, sweating, or every two hours outdoors.
• UPF clothing doesn't wear off like sunscreen, make sure to wash your pieces to protect the fabric from damage.

Also, high-quality pieces from NINI, like our Sheer Jacket, are designed to maintain their UPF rating while still being lightweight and travel-friendly.

Bottom Line: A Perfect Pairing

Think of it this way: SPF is like brushing your teeth, something you have to do repeatedly throughout the day. UPF clothing is more like putting on a seatbelt — once it’s on, it protects you without further thought.

The most effective sun-care strategy combines both. Cover what you can with UPF clothing, and apply SPF everywhere else. If you’re looking to start your UPF wardrobe, try NINI essentials like the Maxi Lace Caftan Dress for sun-shielding , or the Belted Midi Shirt Dress for an everyday city-to-seaside staple.