sun protection factor

noun

|Updated on: 12 Jun 2018

Definition of sun protection factor

: a number assigned to a sunscreen that is the factor by which the time required for unprotected skin to become sunburned is increased when the sunscreen is used —abbreviation SPF

See sun protection factor defined for English-language learners

Recent Examples of sun protection factor from the Web

Legitimate sunscreens are made in a wide range of sun protection factor values, also known as SPF values, and are over-the-counter drugs that come in many forms.

— NBC News, "Sunscreen pills are fake medicine, FDA says," 23 May 2018
Typically, the first line of business is to decide on your level of SPF, or sun protection factor.

— CNN Underscored, "Do your skin a favor with this top-rated sunscreen," 1 Nov. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sun protection factor.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.