The famed magazine -- which prides itself on keeping tabs on stars' fortunes -- says their new tally on the Laker great has now made him an official billionaire ... and he's got change to spare with the title. According to them, Earvin's estimated net worth is around $1.2 bil.

They say his massive wealth post-basketball comes as a result of a hodgepodge of investments he's made over the years -- and if you know anything about Magic, that tracks.

The dude's a partial owner in a number of pro sports teams -- including the Dodgers, the Sparks, MLS' LAFC and more recently ... the NFL's Washington Commanders. Interestingly enough, though, these minority owner stakes aren't what make him rich-rich here.

Apparently, it's Magic's 60% stake in a life insurance company called EquiTrust ... which he snapped up in 2015. The company's been booming in profits since then -- and he's rolling in the dough as a result.

There are more investments Magic's made that tipped him over the edge ... including movie theater chains he's bought into, as well as a Starbucks partnership he entered into a while back. He's also got an extra minority stake in a PepsiCo bottling plant outside of D.C.

Of course, he's also a media mogul ... not to mention an incredibly recognizable face just about everywhere he goes -- which probably helps when he gets booked for appearances.

Like we said, Magic hitting this benchmark puts him in an exclusive group among 3 other athletes in the billionaire stratosphere ... that'd be LeBron James, Tiger Woods and Michael Jordan. Now Magic's there too -- and to be honest, it was probably a long time coming.