UPF Clothing Guide

UPF stands for Ultraviolet Protection Factor. It measures how much UV radiation a fabric allows to reach your skin. A UPF 50+ rating means the fabric blocks at least 98% of UV rays — only 1/50th of the sun's radiation passes through.

SPF (Sun Protection Factor) rates sunscreen and measures protection against UVB rays only (although sunscreens labeled "Broad Spectrum" protect against UVA rays as well). UPF rating measures a fabric's protection against both UVA and UVB rays. In short, SPF is for lotions, UPF is for clothing.

UPF is tested in a lab using a spectrophotometer, which measures how much UV light passes through a fabric sample. In the U.S., the standard test method is AATCC TM 183, and labeling follows ASTM D6603. The fabric is tested in multiple orientations and conditions, including after laundering and simulated sunlight exposure.

UPF 50+ blocks at least 98% of both UVA and UVB radiation. That means only 2% or less of the sun's UV rays reach your child's skin. For context, a typical cotton t-shirt has a UPF of about 5–7, which lets roughly 15–20% of UV through.

Yes. Under U.S. and international standards, UPF 50+ is the maximum rating a manufacturer can claim. A fabric may technically test higher, but it's reported as 50+ — anything above that threshold provides negligible additional benefit.

Yes. UPF clothing is one of the most reliable forms of sun protection available. Unlike sunscreen, it doesn't wash off, wear off, or need reapplication. The protection is built into the fabric itself and is consistent throughout the day.

Fabric blocks UV through a combination of fiber type, weave density, weight, color, and sometimes chemical UV absorbers added during manufacturing. Tighter weaves with less space between threads block more UV. Thicker, denser fabrics naturally allow less light through.

For regular clothing, yes — darker colors generally block more UV than lighter ones. But for clothing specifically engineered and rated for UPF protection, color matters much less. The fabric's construction, fiber type, and any UV-absorbing treatments are doing the heavy lifting, not the dye.

It depends on the fabric. UPF that comes from the fabric's construction (tight weave, dense fibers) tends to hold up well over the garment's life. UPF that relies on chemical treatments can diminish with heavy use and repeated washing, though quality garments are engineered to maintain their rating through many wash cycles.

Generally, no. In fact, some fabrics actually gain a small amount of UPF after washing because the fibers tighten and shrink slightly, closing gaps in the weave. High-quality UPF garments are tested after laundering to ensure they maintain their rating. Avoid bleach, which can degrade fibers.

No. While dark colors do block more UV than white or light pastels, a dark t-shirt is not equivalent to a UPF-rated garment. A standard navy cotton tee might have a UPF of 10–15, which still lets a significant amount of UV through. True UPF clothing is engineered and lab-tested to meet a specific standard.

All clothing provides some UV protection, but the level varies wildly. A sheer white cotton shirt might only offer UPF 3–5, while a heavy denim jacket could be UPF 1,000+. The problem is you have no way to know without testing. UPF-rated clothing removes the guesswork.

Polyester and nylon tend to have the highest natural UPF because their fibers are tightly structured and reflect UV effectively. Wool also scores well. Cotton and linen are on the lower end unless they're woven very tightly or treated with UV absorbers. Bamboo-derived fabrics fall somewhere in between.

Some is, some isn't. There are two main approaches: structural UPF (achieved through fiber type, weave, and weight) and chemical UPF (achieved by applying UV-absorbing compounds to the fabric). Many high-quality UPF garments use a combination of both. If chemical treatments concern you, look for brands that disclose their approach and any certifications like OEKO-TEX.

In the U.S., UPF testing and labeling are governed by voluntary industry standards (AATCC TM 183 for testing, ASTM D6603 for labeling), overseen by the FTC. Australia and New Zealand have a mandatory standard (AS/NZS 4399). The industry is largely self-regulating in North America — which means it's important to buy from brands that can point to actual lab test results, not just a number on a tag.

Fair-skinned children burn faster and are at higher risk for UV damage, so UPF clothing is especially important for them. But all children, regardless of skin tone, benefit from UPF protection.

It can help indirectly. Sun exposure can trigger or worsen eczema flares in some children, so blocking UV with clothing can reduce that trigger. UPF clothing also eliminates the need for sunscreen on covered skin — relevant since many sunscreens contain ingredients that irritate eczema-prone skin. Look for UPF garments made with soft, hypoallergenic fabrics.

They're complementary, not competing. Shade reduces UV exposure but doesn't eliminate it — UV reflects off sand, water, concrete, and other surfaces, reaching your child even under an umbrella. UPF clothing provides an additional layer of protection that goes wherever your baby goes, shade or not.

Significant. Research shows that just one blistering sunburn in childhood or adolescence more than doubles a person's lifetime risk of developing melanoma. While you may have heard the old myth that "80% of sun exposure happens before age 18" (it's actually closer to 25%), early UV damage still significantly contributes to both skin cancer risk and premature skin aging. Protecting your child's skin now has lifelong benefits.

Yes. Unlike SPF sunscreen ratings (which historically focused on UVB), UPF measures protection against the full UV spectrum — both UVA and UVB. UVB causes sunburn; UVA penetrates deeper and contributes to long-term skin damage. UPF clothing blocks both.

Yes. Lightweight, loosely woven, or light-colored regular clothing can allow enough UV through to cause a sunburn, especially during prolonged exposure or at peak sun hours. This is one of the main reasons purpose-built UPF clothing exists.

More than most parents realize. A standard white cotton onesie may have a UPF of only 3–7, meaning 15–30% of UV rays are reaching your baby's skin right through the fabric. Thinner, looser-weave garments perform even worse.

Yes. Up to 80% of UV rays penetrate cloud cover. Overcast days create a false sense of security — your child can absolutely get sunburned on a cloudy day. UPF clothing protects regardless of cloud conditions.

Yes. Skin covered by a UPF 50+ garment is receiving 98% less UV than exposed skin. That's an enormous reduction. While no single measure is 100% foolproof, UPF clothing is one of the most effective sunburn prevention tools available — far more consistent than sunscreen, which can be applied unevenly or missed entirely.

Absolutely. UPF clothing is one of the safest sun protection options for newborns. Unlike sunscreen, it doesn't introduce any chemicals to your baby's skin. Just make sure the garment is soft, breathable, and doesn't overheat your baby — the same considerations you'd have with any newborn clothing.

Yes. The AAP specifically recommends clothing labeled with a UPF rating as part of a comprehensive sun safety plan for children. Pediatric dermatologists consistently recommend UPF clothing as one of the most effective ways to reduce UV exposure in kids.

On skin covered by UPF clothing, yes — no sunscreen needed. But any exposed skin (hands, face, legs, feet) still needs sunscreen or shade protection. UPF clothing and sunscreen work best as a team: clothing handles the large surface areas, sunscreen covers what clothing can't.

Yes, UPF clothing is safer than sunscreen for babies under 6 months. The American Academy of Pediatrics and the FDA advise only using sunscreen on infants as a last resort, because their skin absorbs chemicals more readily. UPF clothing provides passive, chemical-free protection.

From birth. The AAP recommends lightweight, long-sleeved clothing and brimmed hats as the primary sun protection for newborns and infants. Since sunscreen is not recommended for babies under 6 months, UPF clothing is essentially the first line of defense.

Yes. Babies have thinner, more sensitive skin than adults, making them significantly more vulnerable to UV damage. The American Academy of Pediatrics (AAP) recommends keeping babies under 6 months out of direct sunlight entirely and dressing them in protective clothing. UPF clothing is the safest, most reliable way to protect their skin.

Not if it's well-designed. Quality UPF clothing is engineered for outdoor use, which means breathable fabrics, moisture-wicking properties, and lightweight construction. A good UPF garment should feel no hotter — and often cooler — than a comparable piece of regular clothing, because it's designed for exactly this purpose.

Not in a well-made garment. Look for UPF clothing made from lightweight, breathable fabrics. The key is the same as with any baby clothing: avoid overdressing, watch for signs of overheating, and ensure good airflow. UPF doesn't mean thick or heavy — the protection comes from the fabric's construction, not its weight.

Good UPF fabric is very breathable. Many UPF garments use technical fabrics with moisture-wicking and ventilation properties specifically because they're designed to be worn outdoors in warm weather. Not all UPF fabrics are created equal, though — look for garments that specifically call out breathability.

Yes. The best UPF clothing is designed to be worn all day, not just at the beach. Soft hand-feel, four-way stretch, flatlock seams, and tagless labels are all features to look for if you want your child to wear it comfortably from morning to night.

There's no reason a toddler can't nap in UPF clothing if it's comfortable — it's just fabric. For overnight sleep, you'd follow the same safe sleep guidelines you would with any clothing: ensure it's not too warm and fits appropriately. Most parents use UPF clothing during the day and switch to regular sleepwear at night.

It depends on the garment. Some UPF clothing uses technical synthetic fabrics that feel slick or athletic. Others use soft blends that feel like regular everyday clothing. There's a wide range. The best children's UPF garments are designed to feel as soft and natural as the clothes kids already love wearing.

Yes, plenty. Many brands make sub-4-ounce UPF fabrics specifically for summer. Look for terms like "ultralight," "cooling," or fabric weights listed under 150 GSM. These garments provide full UPF protection while feeling barely there.

Not necessarily. UPF protection comes from fabric structure and fiber type, not thickness. Many UPF garments are lighter than a standard cotton tee because they use lightweight synthetic or blended fabrics. Weight varies by brand and garment style, but "UPF" does not mean "heavy."

No. Early UPF clothing sometimes had a stiff or plasticky feel, but modern UPF fabrics have come a long way. High-quality UPF garments feel soft, smooth, and natural against the skin. Always check fabric composition and reviews if texture matters to you.

Lightweight polyester blends and bamboo-derived fabrics tend to perform best in heat because they wick moisture and dry quickly. Look for garments described as "lightweight," "moisture-wicking," or "quick-dry." Avoid heavy cotton UPF garments for peak summer heat.

Absolutely — and that's the point. The best UPF clothing doesn't look or feel like "sun gear." It looks like normal, cute baby and toddler clothing that happens to have built-in UV protection. No need for a special outfit; just make UPF part of the daily wardrobe.

Good UPF clothing shouldn't. Look for garments with stretch fabric and a cut that allows full range of motion. Stiff or overly structured garments can restrict movement, but that's a design issue, not a UPF issue. The best kids' UPF clothing is made for crawling, climbing, running, and everything in between.

Most is, yes. Many UPF fabrics include spandex or elastane for four-way stretch, which is important for active toddlers and kids. Check the product description for stretch content — a blend with 5–10% spandex will move easily with your child.

Both can achieve high UPF ratings. Polyester naturally reflects UV more effectively and dries faster. Bamboo-derived fabrics (usually bamboo viscose or rayon) are softer and more naturally antimicrobial but may need tighter weaves or treatments to achieve UPF 50+. The best choice depends on your priorities: performance and quick-dry vs. softness and feel.

Yes, though it's worth understanding the nuance. Some fabrics lose a small amount of UPF when wet because water can slightly change how the fibers transmit UV. However, a garment rated UPF 50+ when dry will still provide very high protection when wet — far better than bare skin or regular clothing.

If it's designed for water use, yes. Swim-specific UPF garments (rash guards, swim shirts, swim onesies) are made from chlorine-resistant, quick-dry fabrics meant to be worn in the water. Non-swim UPF clothing can get waterlogged and uncomfortable. Always check whether a garment is designated for swim use.

A rash guard is a type of UPF shirt designed specifically for water activities. It's typically made from quick-dry, chlorine-resistant fabric with a snug fit. A UPF shirt is a broader category that includes everyday wear, activewear, and swim shirts. All rash guards should be UPF-rated, but not all UPF shirts are designed for swimming.

It can decrease slightly in some fabrics. Wetting a fabric can change its UV transmission properties. That said, a UPF 50+ garment that drops to UPF 40 when wet is still providing excellent protection — it's blocking over 97% of UV rays. This is why quality matters: well-engineered fabrics maintain high UPF even when wet.

UPF clothing doesn't expire in the sun the way sunscreen does — a UPF 50+ garment provides the same protection in hour one as in hour five. However, exposed skin still needs regular sunscreen reapplication, and children should still take shade breaks and stay hydrated. UPF clothing isn't a free pass to unlimited sun time.

Yes. Water reflects UV rays, increasing your child's exposure. Toddlers at the pool are getting UV from above and from the reflection below. A UPF swim shirt or swimsuit drastically reduces the surface area you need to cover with sunscreen, and provides more consistent protection than lotion that washes off in the water.

Most do. Swim-designated UPF garments are typically made from polyester or nylon blends designed to dry fast. Quick-dry capability is a core feature of swim UPF clothing because nobody wants a kid sitting in a soggy suit. Check for "quick-dry" in the product description.

Over time, chlorine can degrade fabric fibers, which may eventually reduce UPF. Swim-specific UPF garments are made from chlorine-resistant fabrics designed to withstand pool chemicals. Rinsing swim UPF clothing in fresh water after pool use helps extend its life. For non-swim UPF garments, keep them out of the pool.

Saltwater is generally less damaging to fabric than chlorine, but it can still cause wear over time. Rinse all UPF garments with fresh water after ocean use. Salt can also stiffen fabrics if left to dry without rinsing, which affects comfort more than UPF performance.

Absolutely. Splash pads are a prime use case — your child is in and out of water, fully exposed to the sun, and sunscreen washes off quickly. A UPF shirt or onesie is the easiest and most effective way to protect them. It works whether they're wet or dry.

For swim use, a snug (but not restrictive) fit is best. Snug-fitting swim UPF clothing stays in place in the water, doesn't balloon or ride up, and maintains consistent fabric-to-skin contact for UV protection. Loose swim clothing can drag in the water and create safety issues for small children.

Yes. UPF clothing only protects what it covers. Any exposed skin — face, hands, lower legs, feet, ears — still needs sunscreen, a hat, or shade. Use broad-spectrum SPF 30+ on all uncovered areas and reapply every two hours or after your child gets out of the water.

No. UPF clothing protects against UV — wetsuits protect against cold water by trapping a layer of water against the skin. They serve completely different purposes. A rash guard worn under a wetsuit can help prevent chafing while adding UV protection during surface time, but it won't keep your child warm in cold water.

Structural UPF fabrics, like the ones used in Dillos, achieve UPF from the fabric itself and hold up indefinitely. Chemical UPF treatments can diminish with each wash, and the useful life depends on the brand and number of washes.

It can. Fabric softener coats fibers, which may alter UV transmission properties in some fabrics. More practically, fabric softener can reduce moisture-wicking performance. Skip it for UPF clothing — these garments don't need it and perform better without it.

Yes. Hand washing in cool water with mild detergent is the gentlest option and can extend garment life. Rinse thoroughly and air dry for optimal results.

Like any clothing, it depends on fabric quality and care. Higher-quality garments resist pilling and fading much better. Washing inside-out and air drying helps prevent both.

Unfortunately, many UPF brands use chemical treatments to achieve UV resistance, which can wash out after several washes. Dillos UPF protection will last as long as the fabric itself. In general, if the garment has too many holes, it might be time to replace it.

Avoid bleach when washing UPF clothing, as it can damage the fabric. Use a mild, bleach-free detergent instead. For stains, try spot-treating with a gentle stain remover or detergent.

You probably shouldn't iron UPF fabrics since high heat can damage most synthetic and stretch fabrics. To get wrinkles out, opt for a steamer instead.

A well-made UPF garment should last as long as the child fits in it and be able to be passed down. Unlike cheaper spray-treated garments, the UPF protection in Dillos is built into the fabric and doesn't "expire."

It depends on the fabric. Polyester and nylon UPF garments, like Dillos, generally resist shrinking. Cotton or other natural fibers used can shrink if washed in hot water or dried on high heat.

Most can go in the dryer on low heat, but air drying is gentler on the fabric and will extend the garment's life. High heat can damage stretch fibers like spandex. When in doubt, check the care label.

Machine wash UPF fabrics cold on a delicate cycle with mild detergent. Avoid bleach and fabric softener. If the garment is swim-specific, rinse it in fresh water first to remove chlorine or salt.

Not inherently, though some UPF garments include stain-resistant or easy-release finishes. Synthetic UPF fabrics (polyester, nylon) tend to resist stains better than natural fibers. For baby and toddler clothing, assume it will get messy — stain resistance is a bonus, not a guarantee.

Maybe, but there's a catch. Some brands claim to use organic cotton blends or sustainably sourced fibers in their UPF lines, but cotton is poor at blocking UV. These garments often get a chemical UV treatment to achieve UPF 50+, so verify the rating rather than assuming "organic" equals "protective" or "better".

The range has expanded significantly to include onesies, rompers, long-sleeve shirts, hoodies, leggings, swimsuits, rash guards, hats, and more. You can build a full wardrobe around UPF clothing without sacrificing style or variety.

Yes, many brands offer UPF clothing in neutral colors and unisex cuts. Babies and toddlers don't need gendered sun protection. Look for brands like Dillos that focus on function and design rather than pink ruffles vs. blue trucks.

They should, but not all do. Some brands print "UPF 50" on a tag without independent lab verification. Reputable brands, like Dillos, test their fabrics through accredited labs using AATCC TM 183 or equivalent standards and can provide test documentation. If a brand can't tell you who tested their fabric, that's a red flag.

The right size should allow your child room to grow into it. UPF protection comes from the fabric, not the fit, so a slightly larger garment still protects. Dillos are designed with a roomy fit to accommodate growing kids.

Often, yes. More expensive UPF clothing typically uses higher-quality fabrics that feel better, last longer, and maintain their UPF rating through more wear and washes. Cheaper options may use lower-grade materials, offer less comfort, or rely on chemical UV treatments that fade faster. Price alone doesn't guarantee quality, but you often get what you pay for.

Look for brands like Dillos that specialize in sun protection rather than brands that added a UPF line as an afterthought. Key differentiators include UPF lab testing, thoughtful design (fold-over footsies, built-in hat), and a focus on the specific age group you need.

Five things: (1) a verified UPF rating, (2) soft, breathable fabric appropriate for your child's climate, (3) a cut and fit that allows free movement and airflow, (4) quality construction (reinforced seams, colorfast dyes), and (5) a brand that can back up their UPF claims with real test data.

Yes. Consider what you're replacing: constant sunscreen reapplication (which costs money, time, and a toddler meltdown every two hours), plus the peace of mind that covered skin is actually protected. A single UPF garment protects reliably all day, every day, for the life of the garment. Compare that to a $15 tube of sunscreen that lasts a few weeks.

Online is your best bet for the widest selection. Specialty DTC (direct-to-consumer) brands like Dillos tend to offer the best quality and highest UPF ratings. You can also find UPF clothing at major retailers, outdoor recreation stores, and children's boutiques. Always verify the UPF rating before buying — not all "sun protection" clothing is actually UPF-rated.

Dillos don't come in premie sizing right now. For very small babies, lightweight UPF blankets or wraps can provide coverage. Since preemies should be kept out of direct sun entirely, the need is typically for indirect protection during transport or brief outdoor time.

Dillos have a roomy sizing that should fit at the top of the size range, even for larger kids. The UPF protection doesn't change with a slightly looser fit.

For everyday wear, we recommend a roomy fit to allow airflow, but the UPF-rated fabric protects regardless of how snug it is against the skin. For swim use, a snug fit keeps the garment in place in water.

UPF 50+ whenever possible. It blocks 98%+ of UV rays and is the highest rating available. UPF 30 (blocking ~97%) and UPF 15 (blocking ~93%) are labeled "Very Good" and "Good" respectively, but for babies and young children, there's no reason not to go with the maximum protection.

UPF clothing costs more because it requires engineered fabrics (specific fiber types, weave densities, and sometimes UV-absorbing treatments), third-party lab testing to verify the UPF rating, and often more specialized manufacturing. You're paying for a performance garment, not a basic commodity tee.

Yes — a hood covers the back of the neck and, when up, ears and the side of the head, areas that crew necks leave fully exposed. A UPF hoodie is essentially a shirt plus partial hat coverage in one garment. Dillos Sun Onesies have the hood and hat built in.

Yes. Dillos Sun Onesies are engineered for babies and toddlers. UPF onesies are one of the best options for babies because they provide full coverage in a single garment. A UPF onesie paired with a hat covers the majority of your baby's skin, leaving only the face, hands, and lower legs for sunscreen.

All skin can burn, but the shoulders, upper back, chest, and arms get the most direct sun exposure during outdoor play. The neck and ears are also commonly burned. A long-sleeve UPF top and a hat cover the most critical zones.

Yes! A UPF layer over or under regular clothing still provides protection. Layering is a great way to stay comfortable and protected throughout the day.

Yes. The days of UPF clothing looking like a lifeguard uniform are over. Many brands offer fun prints, bright colors, and stylish designs that kids actually want to wear. UPF technology has advanced to the point that it no longer constrains design choices.

Yes. A hat protects the face, ears, and back of the neck — areas that are hard to cover with clothing and easy to miss with sunscreen. Look for a UPF-rated hat with a wide brim (at least 3 inches) that shades the face, ears, and neck. The AAP specifically recommends brimmed hats as part of sun protection for children. Dillos sun onesies have the hat built in.

Long sleeves are better. They cover more skin and eliminate the need for sunscreen on arms, but a short-sleeve UPF shirt is still far better than a regular cotton t-shirt. Dillos are designed to release heat to make long sleeves comfortable in hot weather.

As much as practical. The more skin covered, the less sunscreen you need to apply and the better protected your child is. Long sleeves and full-length legs provide the most coverage. At minimum, cover the torso and shoulders — these large surface areas are the most efficient to protect with clothing.

A stroller canopy helps but doesn't fully protect. UV reflects off pavement, sand, water, and other surfaces, reaching your baby from below and from the sides. A canopy blocks direct overhead sun, but UPF clothing protects against reflected and ambient UV from all angles. Use both together for the best protection.

Yes. Playing or watching outdoor sports means prolonged, often intense sun exposure. Many youth sports organizations are beginning to encourage or require sun-protective clothing during practice and games.

Yes, more so than at sea level. UV intensity increases about 4–5% for every 1,000 feet of elevation gain. A family hiking or skiing at 8,000 feet is getting 30–40% more UV than at sea level. UPF clothing is especially important in mountain environments.

Standard car side windows block UVB but allow most UVA to pass through. If your child sits by a window during a long car ride, they can be exposed to UVA. UPF clothing provides protection, though a window shade is also effective and easier to manage. For long drives in sunny conditions, it's worth considering both.

It can be. UV rays are present year-round, and snow and water can reflect up to 80% of UV, effectively doubling exposure. If your child is outdoors in winter sun for extended periods, UPF protection is worth considering. In cloudy, northern winters with minimal outdoor time, it's less of a concern.

If your child plays outside at daycare, yes. Daycare providers are often managing multiple children and can't guarantee consistent sunscreen reapplication. UPF clothing provides set-it-and-forget-it protection — dress your child in UPF in the morning and know they're covered all day without relying on anyone else to reapply lotion.

Yes, especially for field days, outdoor PE, recess, and field trips where extended sun exposure is likely. A UPF shirt is easier than relying on kids to reapply sunscreen. Many schools have sun-safety policies that welcome UPF clothing.

Your cart is empty

Complete Guide to UPF Clothing