How hot was the iPhone 4 in Q4?

With supply levels uncertain, analysts' unit sales estimates are all over the lot

Almost lost amid the onslaught of Google (goog) Android devices and rumors about a Verizon (vz) iPhone is that fact that Apple (aapl) -- despite all that Antennagate talk -- just closed its books on the biggest iPhone quarter ever.

How big? That's the multi-billion dollar question.

Of all its products, none is more important to Apple's bottom line than its smartphone, which generated $5.4 billion in fiscal Q3 -- 40% of the company's total revenue. The iPhone 4, launched three days before the end of that quarter, has been in short supply ever since, making it trickier than usual for analysts trying to estimate sales in advance of Apple's quarterly earnings report.

"The EPS Derby," writes Jeff Fossberg, an independent analyst who posts on the Mac Observer's Apple Finance Board, "will be won by the one who nails iPhone units."

The Q4 iPhone estimates of the analysts we've polled vary wildly, from a low of 10 million units from Morgan Keegan's Tavis McCourt to a high of 13.3 million from Rodman & Renshaw's Ashok Kumar. At the low end, that represents a 35.7% increase from Q4 2009. At the high end, it's more like 80% year over year.

We've used the average, 11.8 million (up 60%), in the bar chart above.

Below: The unit sales estimates (in millions) we've gathered so far. We'll find out who was closest after the closing bell on Oct. 18.

<!-- more -->

Analyst, affiliationiPhones (millions)Date of est.
Ashok Kumar, Rodman & Renshaw13.3010/6/10
Matthew Hoffman, Cowen & Co.13.109/14/10
Horace Dediu, Asymco13.009/28/10
Ben Reitzes, Barclays Capital12.809/29/10
Alexis Cabot, Apple Finance Board12.5810/1/10
Daniel Tello, Deagol's AAPL Model12.519/29/10
Kathryn Huberty, Morgan Stanley12.5010/7/10
Chris Whitmore, Deutsche Bank12.5010/4/10
Robert Cihra, Caris & Co.12.409/23/10
Robert Paul Leitao, Apple Finance Board12.3010/1/10
Nicolae Mihalache, Traderhood12.2510/1/10
Brian Marshall, Gleacher & Co.12.009/28/10
Turley Muller, Financial Alchemist11.9010/7/10
Doug Reid, Stifel Nicholaus11.649/30/10
Jeff Fidacaro, Susquehanna11.639/22/10
Jeff Fosberg, Apple Finance Board11.609/30/10
Keith Bachman, BMO Capital11.5010/6/10
Shaw Wu, Kaufman Bros.11.509/20/10
Andy Zaky, Bullish Cross11.509/29/10
William Fearnley, Janney Capital11.308/25/10
T. Michael Walkley, Canaccord Genuity11.109/27/10
Yair Reiner, Oppenheimer10.509/29/10
Dennis Hildebrand, Apple's Gold10.479/28/10
Rajesh Ghai, Think Equity10.0810/5/10
Tavis McCourt, Morgan Keegan10.0010/4/10

. . .
See also:

[Follow Philip Elmer-DeWitt on Twitter @philiped]

All products and services featured are based solely on editorial selection. FORTUNE may receive compensation for some links to products and services on this website.

Quotes delayed at least 15 minutes. Market data provided by Interactive Data. ETF and Mutual Fund data provided by Morningstar, Inc. Dow Jones Terms & Conditions: S&P Index data is the property of Chicago Mercantile Exchange Inc. and its licensors. All rights reserved. Terms & Conditions. Powered and implemented by Interactive Data Managed Solutions