The album-equivalent unit, or album equivalent, is a measurement unit in music industry to define the consumption of music that equals the purchase of one album copy. This consumption includes streaming and song downloads in addition to traditional album sales. The album-equivalent unit was introduced in the mid-2010s as an answer to the drop of album sales in the 21st century. Album sales more than halved from 1999 to 2009, declining from a $14.6 to $6.3 billion industry, partly due to cheap digitally downloaded singles. For instance, the only albums that went platinum in the United States in 2014 were the Frozen soundtrack and Taylor Swift's 1989, whereas several artists' works had in 2013.

An album is a collection of audio recordings issued on a medium such as compact disc (CD), vinyl (record), audio tape, or digital. Albums of recorded sound were developed in the early 20th century as individual 78 rpm records collected in a bound book resembling a photo album; this format evolved after 1948 into single vinyl long-playing (LP) records played at 33+1⁄3 rpm.