Apple’s the most valuable, publicly-traded company of all time? Only if you ignore inflation…

There’s news all around today about how Apple is the most valuable publicly-traded company of all time. The record was previously held by Microsoft, with a total market cap of $618.89 billion, but today Apple surpassed that figure, totaling $620.66 billion as of the time of this writing.

The only problem here is that nobody seems to be accounting for inflation, and you absolutely have to or else you end up with a number that, while impressive, doesn’t mean a whole lot. So what happens if you take Microsoft’s 1999 market cap of $618.89 billion and adjust it?

In inflation-adjusted dollars, Microsoft was worth about $850 billion on Dec. 30, 1999. It is now worth $257 billion

— Horace Dediu (@asymco) August 20, 2012

There’s absolutely no denying that what Apple has managed to do is astounding. It’s a feat worthy of every accolade that has come its way, but we have to make sure that the cheers are accurate. A dollar bought you a lot more in 1999 than it does in 2012 and only an adjusted market cap will reflect that.

Now let’s make things doubly interesting by looking at where Microsoft is today – $257.54 billion. Again, with the adjustment for inflation, the company has lost almost 3/4 of its market cap over the course of the past 13 years since setting its record. Though Microsoft is having what is arguably the most exciting year of its life right now, it’s hard to compete with Apple’s 300 million annual retail store visits and sales increases while the rest of the personal computer market flounders.

While I sometimes hate to be the bearer of reality, it’s important to keep things in perspective. Apples to apples, so to speak.

Image: TaxCredits.net