How many Macs did Apple sell last quarter?

January 12, 2013, 11:27 PM UTC
Click to enlarge. Chart: PED

FORTUNE (Vientiane, Laos) — At first glance, the chart at right looks pretty dismal. It suggests that Wall Street expects Christmas quarter sales of the Mac to grow less year over year than any year in memory, and that our sample of independent analysts — generally more bullish than the professionals — expect year over year unit sales to actually fall.

Two points:

1. These numbers don’t take into account the fact that Q1 2012 had 14 weeks of Mac sales, not the usual 13. When the forecasts are adjusted for the shorter quarter, both groups come out with positive growth numbers — 10% for the pros, 5% for the independents. That’s considerably less than last Christmas’ 26%, but it does represent growth in a year in which everybody else’s PC sales are shrinking.

2. Before he died, Steve Jobs launched Apple (AAPL) on a multiyear effort to disrupt the PC industry — including its own personal computer business — with smartphones and tablet computers. That’s what a disruptive company is supposed to do. If the iPad fulfills its promise, Mac sales should go down.

With that out of the way, let’s take a second look at the numbers. The high estimate of 6.5 million, from Braeburn’s Nick Nansen, represents 35% growth year over year (adjusted for the shorter quarter). The low of 4.45 million, from Navin Arthanareeswaran, another Braeburn indy, works out to -8%.

The median estimate — 5.2 million — looks like the same number Apple reported in Q1 2011. But adjusted for that quarter’s extra week, it actually represents 8% growth.

Below: The individual analysts estimates, with the pros in blue and the indies in green. We’ll find out who was closest to the mark on Wednesday Jan. 23, when Apple reports its earnings for fiscal Q1 2013.

Note: An earlier version of bar chart above incorrectly listed Q2 2012 unit sales as 5.34 million, not 4.92 million.