· By WLAM
What does UPF 50+ mean? Choosing sun-protective sportswear for outdoor play
Playing pickleball, tennis or golf in Vietnam means standing in the sun for hours. Sunscreen washes off with sweat; your shirt stays put. That is why the UPF rating on a shirt is worth understanding properly.
How UPF differs from SPF
SPF is for sunscreen. UPF (Ultraviolet Protection Factor) is for fabric and tells you how well it blocks ultraviolet rays. According to the Skin Cancer Foundation (US), UPF covers both UVA and UVB rays, both of which contribute to skin cancer.
What UPF 50 means
A UPF 50 fabric lets through only about 1/50 of UV rays, blocking about 98%. For comparison, the Skin Cancer Foundation says a regular white T-shirt has a UPF of only about 7.
| UPF | Skin Cancer Foundation | AS/NZS 4399 standard (Australia, New Zealand) |
|---|---|---|
| 15–29 | – | Minimum protection (from 15) |
| 30–49 | Very good | Good protection |
| 50 and 50+ | Excellent | Excellent protection |
A note from the University of Arizona: a shirt labeled 50+ doesn't necessarily protect much better than UPF 50. Beyond 50, the difference is very small.
What the UPF number doesn't tell you
- UPF rates the fabric, not the design. The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) notes that test reports rate only the material, not the cut or coverage. A short-sleeved UPF 50 shirt still leaves your arms exposed.
- Wet or stretched fabric protects less. According to the Skin Cancer Foundation, wet or stretched fabric becomes more see-through and blocks less UV. So choose a size that fits, not one that is too tight.
- Cover as much as you can, including your head: wear a hat and sunglasses, and put sunscreen on exposed skin.
Pick your playing time by the UV index
The UV index scale proposed by the WHO and international partners rates 11 and above as "extreme". At that level, the US National Weather Service advises avoiding the sun from 10 a.m. to 4 p.m., seeking shade and covering up well. Check the UV index in your weather app before booking a court.
UV protection of WLAM shirts
- 01W228 · Contrast Trim Zip Polo: the fabric tested at UPF 447 (rated UPF 50+), letting through only 0.24% of UVA and 0.18% of UVB.
- 01W226 · Striped Zip Polo: the fabric tested at UPF 90 (rated UPF 50+).
- 02W219 · Tipped Collar Polo: the manufacturer's printed label states UPF 50+.
Read more: what to wear for pickleball.