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UV Protective Shirts, Explained

After reading, you'll understand what a UPF number means, what changes it, and how to spot a shirt that does not state one.

Updated October 9, 2026 · Companion to our Outdoors & Fitness review

Coolibar Aricia Men's Long Sleeve Shirt - our top pick
In this guide

Sun shirts look like ordinary athletic shirts, so first-time buyers often assume any technical fabric protects them. In fact only a printed UPF rating tells you what the fabric blocks. Fabric, color, fit and wetness all change the result, and makers differ on whether they say the rating lasts. Collars, hoods and thumb holes decide which skin is covered. This guide explains the terms so you can read a product page with confidence.

The 30-second version

  • UPF is a fabric number, and a shirt that prints no number gives you nothing to check.
  • UPF 50+ is the target, which the Skin Cancer Foundation says rates as excellent.
  • Stretched or wet fabric protects less, so size for a relaxed fit.
  • Wash claims are rare, and Coolibar is one maker that states a figure of up to 40 wash cycles.
  • Shirts leave skin out, so a hat and sunscreen still matter.

The products this guide is about

Our verdict on each, with the full reasoning on the companion review.

What actually matters

  • UPF rating - This is the number that says how much UV the fabric blocks. A higher number means less reaches your skin, and 50+ is the top of the usual scale.
  • Fabric blend - The fibers and weave decide how much light passes through. Synthetic knits and tight weaves are common in sun shirts, while thin cotton passes more.
  • Wash durability - Makers rarely state how long a rating lasts. A wash claim, when printed, tells you the maker has thought about it.
  • Fit - A shirt pulled tight across the shoulders stretches the weave and passes more light. A relaxed fit keeps the fabric in its tested state.
  • Neck coverage - A collar flap, a hood or a crew neck each leave different skin exposed. Pick based on whether you wear a hat.
  • Hand coverage - Thumb holes pull cuffs over the backs of your hands. These areas get a lot of sun on boats and trails.
  • Color and ventilation - Darker or brighter colors can block more, and some makers give a different rating by color. Vents and light knits keep a long sleeve wearable in heat.

The specs, in plain English

UPFUltraviolet Protection Factor is a rating for fabric. A UPF 50 fabric lets about one-fiftieth of the sun's rays through, so it blocks about 98 percent.
UPF 50+The top label on the usual scale, which the Skin Cancer Foundation rates as excellent. It is the figure to look for on a hiking or fishing shirt.
UPF 20+ or 30Lower ratings on the same scale. The Skin Cancer Foundation calls a UPF of 30 to 49 very good, and a lower stated figure means more light passes.
Polyester and nylonSynthetic fibers common in sun shirts. They dry fast and can hold a tight weave, which helps a rating.
Viscose or bamboo blendA soft fabric made from plant fibers. It feels good but is less common in high-rated sun shirts, as the Free Fly shows with its stated UPF 20+.
SpandexA stretch fiber added in small amounts. It gives movement but can thin the weave if the shirt is cut tight.
Sun flapA hidden panel at the collar that folds up to cover the back of the neck, as on the Coolibar Aricia.
Thumb holesSmall openings at the cuffs that hold the sleeves over the backs of your hands. They add coverage where sun lands on a boat or trail.
Wash cycle guaranteeA maker's statement of how many washes the rating should survive. Coolibar states up to 40, depending on care and use.

Green flags vs red flags

Green flags

  • A UPF number printed on the maker's own product page
  • A listed fabric blend with percentages
  • A stated wash or durability claim
  • A collar flap, hood or thumb holes for neck and hands
  • Fit described clearly with a size chart

Red flags

  • Words like sun protection with no UPF number
  • A blank or missing composition line
  • Very thin, loose or all-cotton fabric
  • A rating that varies by color with no explanation
  • A fit so tight the fabric stretches across the shoulders

Who's who: the brands

  • Coolibar - A sun-protection specialist that states UPF 50+ across its products and a wash cycle guarantee.
  • Outdoor Research - An outdoor brand with a sun line that prints UPF ratings and fabric blends on product pages.
  • Free Fly - A lifestyle fishing brand known for soft bamboo blend hoodies with lower stated ratings.
  • Simms - A fishing brand with a wide range, including SolarFlex shirts that state UPF 50+.

How to read a listing without getting fooled

Start on the maker's own product page, not a retailer listing. Find the printed UPF number first, then the composition line, then any note about washing or color. Read the fit description and size chart, since a tight fit lowers protection. Check the collar or hood and whether the cuffs have thumb holes. If a page says sun protection or fast-dry with no number, treat the shirt as unrated, however good the pockets look. Compare the same details across shirts so you are judging like with like.

How much should you spend?

Sun shirts span the budget, mid-range and premium tiers. Budget tees from outdoor brands can state UPF 50+, so paying more is not required for the rating. Mid-range shirts add collars, vents and sometimes a wash claim. Premium fishing shirts add pockets and styling, and some do not print a rating, so confirm the number before you pay for the name.

Questions, answered

Is a dark shirt always safer than a white one?

Not always. The Skin Cancer Foundation says dark or bright colors absorb UV and help, but fabric and weave matter too. Some makers give a different rating by color, so check the page for the shade you are buying. A white shirt with a stated UPF 50+ beats a dark shirt with no rating.

Can I wear a cotton T-shirt instead?

You can, but it protects less. The Skin Cancer Foundation says a regular T-shirt can fall to a UPF of only 3 when wet. A rated synthetic shirt is the better choice for water days and sweaty hikes.

How do I wash a sun shirt?

Follow the care label. Coolibar advises cold water with gentle detergent, no bleach or fabric softener, and line drying. Heat and harsh products can wear a fabric faster. Replace a shirt that looks thin or has stretched out.

Do hoods and thumb holes really help?

They add coverage in places a basic shirt leaves open. A hood covers the neck and can fit over a cap, and thumb holes cover the backs of your hands. They are most useful on boats and open trails where sun hits from all angles.

Ready to choose? See our top pick, the alternatives, and the one we'd skip See the UV Protective Shirts verdicts

Or jump to the head-to-head: Coolibar Aricia Men's Long Sleeve Shirt vs Outdoor Research ActiveIce Spectrum Sun Long Sleeve Tee.

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