What sales milestone did Metallica become the first album to pass in the Nielsen SoundScan era?

Metallica became the first album to pass 16 million sales in the Nielsen SoundScan era.

Nielsen SoundScan began tracking US music sales in 1991, the same year Metallica was released. The album’s sustained popularity allowed it to keep selling long after its initial chart peak, eventually surpassing every other release in the era’s US sales totals.

By 2016, Metallica had sold 16.4 million copies in the United States according to the figures cited for the album. Cassette sales were especially notable, accounting for 5.8 million copies of that total.

The 16-million milestone is different from the album’s later certification status. In 2025, the Recording Industry Association of America certified Metallica 2× Diamond for US shipments of 20 million copies. One figure describes tracked sales; the other describes an industry certification based on shipments.