Fortune ran its usual poll of more than two dozen analysts, with the consensus view echoing earlier predictions that Apple will beat its revenue guidance of $36-38B by reporting $38.4B for its fiscal Q3 (calendar Q2). Gross margin is also expected to exceed Apple’s guidance of 37-38 percent, at 38.1 percent. This follows forecasts that iPhone sales would climb 15 percent year-on-year, while iPad sales will be flat.

Business Insider reports that Wall Street is once again expecting significant growth from AAPL.

46 Apple analysts rate the stock a buy, 13 call it a hold, and only 4 thinks it’s a sell. Citigroup, which was bearish on the stock, changed its analyst coverage and rated the stock a new “buy.” JMP securities upgraded the stock to outperform Monday morning. Other analysts have raised their price target …

Although fiscal Q3 iPhone sales are generally quiet, with everyone waiting for the new model in September, Chinese and Japanese sales are expected to offset this factor this year.

As with forecasts of iOS devices, predictions of Q3 Mac sales were pretty diverse, ranging from Credit Suisse’s 3.53 million to Janey’s 4.3 million. The average estimate of 3.9M would represent year-on-year growth of 4.2 percent, and would mean “Mac shipments […] outpaced PC shipments for the 32nd time in 33 quarters.”

Sherri Scribner at Deutsche Bank says that might not be a huge drag on the iPhone this year because, “Over the past year, Apple has added 51 new carrier relationships, including China Mobile (with 785 million subscribers) and NTT DoCoMo.”

While Mac sales are typically seen as of largely academic interest compared to iPhone and iPad sales, Needham’s Charlie Wolf says this may not always be the case.

On revenue forecasts, Elmer-DeWitt noted that the gap between the amateurs and pros has substantially narrowed over the years.

“Even though the Mac’s share of the PC market has increased from 1.8% to 5.5%, it is still miniscule,” he writes. “We estimate the Mac’s installed base has increased from 16 million users to over 50 million courtesy of the halo effect. However, this does not imply the halo effect will fade. Apple now has over 800 million credit cards on file. The company has sold over 500 million iPhones and over 200 million iPads. So that’s a substantial group of consumers who have yet to decide between a Mac and a PC.”

Fortune notes that Apple’s gross margins are largely dictated by how much it is spending on tooling-up for new products.

Apple will announce the actual numbers on tomorrow at around 1.30pm PT/4.30pm ET, with its conference call to discuss the results starting half an hour later. We will, of course, bring you live coverage.

Apple’s gross margins tend follow their own internal rhythms, falling when the company is tooling up to build new products and rising as efficiencies increase and component prices fall.

Gross margins peaked in Q2 2012 at an extraordinary 47.4% on the strength of sales of iPhone 4S and dropped to below 37.9% in Q3 2013 as Apple was gearing up to launch, in the same quarter, two new iPhones and pair of iPads.

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