UPF 30 vs 40 vs 50+: what is the difference?

Shopping for sun protective clothing, you will see UPF 30, UPF 40, UPF 50 and UPF 50+. Is the difference worth worrying about? Here is a plain comparison, so you can choose with confidence.

First, what UPF means

UPF tells you how much of the sun's UV gets through a fabric. The higher the number, the less gets through. To find the fraction, divide one by the number. So UPF 50 lets through one fiftieth of the UV, which is 2%.

UPF is for fabric. SPF is for sunscreen. They are different tests, and our guide to UPF vs SPF explains why.

The numbers side by side

On paper, 96.7% and 98% look almost the same. The better way to compare is to look at what gets through. UPF 30 lets through about 3.3% of the UV. UPF 50 lets through 2%. That means a UPF 30 fabric lets through roughly two thirds more UV than a UPF 50 fabric. Over a four-hour round or a long day in the garden, that difference adds up.

A simple way to picture it

Say you are out for a four-hour round on a sunny day. With a UPF 30 fabric on your arms, about 3.3% of the UV reaching the fabric gets through to your skin. With UPF 50+, it is under 2%. Neither number is zero. That is why Cancer Council recommends clothing as one of five steps, together with sunscreen, a hat, shade and sunglasses. The rating tells you how good the fabric is. It does not tell you to skip the rest.

Where did UPF 40 go?

You may notice UPF 40 is missing from Australian guidance. According to Cancer Council, the current Australian standard has only four ratings: UPF 15, 30, 50 and 50+. ARPANSA groups them as Minimum (15), Good (30) and Excellent (50 and 50+).

You can still see UPF 40 on labels. It may come from an older version of the standard, or from clothing tested under overseas rules, including in the US. The maths in the table above still works for any number. If you see UPF 40, it blocks about 97.5% of UV.

Which should you choose?

Cancer Council recommends UPF 50 and 50+, which sit in the Excellent protection group. If you spend long, regular hours outside, such as golf, bowls, gardening, fishing or long drives, choose 50 or 50+ where you can.

A lower rating is still better than bare skin. Cancer Council also points out that fabric does not need a UPF label to give some protection. A tightly made, darker shirt will usually do more than a thin, loose, light one. A UPF label simply tells you how much, because someone has tested it.

What matters as much as the number

A high rating only helps if the garment is doing its job. Check these too:

• Coverage. The rating only applies to skin under the fabric. Look for gaps at the neck, wrists and upper arms.
• Fit. Stretching a knitted fabric usually lowers its UPF, says ARPANSA, because the gaps open up. A garment that is too tight can protect less than its label.
• Moisture. Cancer Council says fabrics protect less when wet. On a sweaty day, a dry spare helps.
• Condition. Old, thin or faded clothing may protect less over time. Replace it when it looks worn.
• Who tested it. Anyone can print a number on a label. Look for details of the test: who did it, when and on what sample.

Where IceRays sits

IceRays sleeves were tested by ARPANSA in 2015 (black sample). The report, reference 10484-1B, rated a Black Aqua-x/Spandex sleeve sample UPF 50+, the Excellent group. The test covered that black sample, and the report rates the material, not the sleeve design. See the full details on our test report page (PDF, opens in a new tab).

One size fits all adults, and the fabric is made to sit smoothly without overstretching. A 4-pack is AUD 120, which is $30 a pair and saves $31.80 compared with four single pairs. In the US it is USD 100.

Want to go further? Read what UPF 50+ means, do arm sleeves protect from the sun?, does sleeve colour matter? and the complete guide to UV arm sleeves.