UPF

American

abbreviation

ultraviolet protection factor: the effectiveness of clothing fabrics in protecting the skin from the sun’s ultraviolet UVA and UVB radiation, rated on a scale of increasing protectiveness, the number being the ratio of the radiation dose needed to produce minimal redness when wearing the fabric compared to the dose needed to produce the same redness when not wearing it.

A shirt with a UPF of 50 will reduce your ultraviolet exposure by 50 times (98% UV blockage).
ultra-processed food.

Etymology

Origin of UPF

UPF as "ultraviolet protection factor" first recorded in 1985–90

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

UPF

To estimate UPF consumption, the researchers analyzed two 24-hour dietary recalls from each participant and calculated the share of daily calories that came from ultra-processed foods.

From Science Daily ● Aug. 27, 2026

At worst, eating a diet of 100 percent UPF compared to a diet with no UPF might cause you to gain a few pounds, but even that is uncertain.

From Slate ● Jul. 12, 2026

Look out for fabrics that are best at blocking radiation from the sun, labelled "UPF 50".

From BBC ● Jun. 19, 2026

In addition, the report says healthcare professionals should encourage patients to reduce UPF consumption alongside standard advice about exercise, smoking, alcohol use, and overall nutrition.

From Science Daily ● May 10, 2026

A watered-down definition, meanwhile, could end up allowing certain ultraprocessed foods to fly under the radar, especially if food companies find a way to get around whatever UPF definition or label is proposed.

From MarketWatch ● Mar. 23, 2026

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023