How many weeks did the longest-charting song spend on the Billboard Hot 100?

How to get close to this number

Anchor on a typical chart run and then ask how far an outlier can stretch. The explanation gives the baseline: most hits are gone within a few months. Records in this kind of distribution usually sit several times the typical value rather than ten times it, which brackets the answer at somewhere around two years on the chart.

The reason people guess low is that they are remembering the pre-streaming era. A song used to leave the chart when it stopped selling, and sales collapse quickly once a single is no longer promoted. Streaming removed that cliff: a track that keeps being played keeps charting, almost indefinitely, so chart longevity records now describe listening habits rather than retail.

That change also makes this a record about a moving definition. The Hot 100 has existed since 1958, but the formula behind it has been rewritten repeatedly to absorb radio airplay, digital sales and then streaming, and rules have been added specifically to stop old songs occupying the chart forever. The run that set this record ended when one of those rules was tightened, not when people stopped listening. Comparing a run from the 1960s with one from the 2020s is comparing two different measurements with the same name.