Apple is scheduled to release its March quarter earnings report after closing bell tonight, and investors appear to be expecting upside to estimates. Analysts certainly are expecting the company to beat its guidance for revenue, but as always, Wall Street will be looking down to the nitty gritty to determine how well Apple Inc. (NASDAQ:AAPL) is doing.

Apple Inc. (AAPL) Earnings Preview: The Devil's In The Details

Apple (AAPL) expected to beat revenue estimates

Apple Inc. (NASDAQ:AAPL) guided for revenue of between $52 billion and $55 billion for its second fiscal quarter, but RBC Capital analyst Amit Daryanani and his team are expecting to see $55.4 billion. Cantor Fitzgerald analyst Brian White is expecting $56.7 billion in revenue for the quarter. He recently upped his estimate from $56.2 billion. The consensus estimate is $55.9 billion, according to White, but $55.2 billion according to Daryanani.

White also increased his earnings estimate from $2.13 to $2.18 per share. The RBC team is expecting earnings of $2.14 per share. The consensus estimate is earnings of $2.11 according to Daryanani but $2.15 per share according to White.

Eyes on the iPhone

Of course Wall Street will also be watching Apple Inc. (NASDAQ:AAPL)’s iPhone unit number very closely. Daryanani said he thinks the sell-side is looking for 56 million iPhone units while the buy-side is expecting about 60 million units. They may be a bit high on that buy-side estimate, however.

White, known for his ultra-bullish stance and high $180 per share price target on Apple Inc. (NASDAQ:AAPL), has increased his estimate significantly from 53.75 million to 58 million unit—coming up short of what Daryanani’s team believes the bulls are looking for. White also slashed his estimates for the iPad from 15.5 million to 14 million units and their Mac units from 4.69 million to 4.31 million units.

Other details in Apple’s (AAPL) earnings report

In addition to iPhone units, investors will also be looking for details on Apple’s gross margin and management commentary on topics like the Apple Watch ramp. The RBC team expects Apple Inc. (NASDAQ:AAPL) to surprise to the upside on gross margin as well, possible with a margin of at least 39%.

The reasons for the expected upside include better pricing and efficiency in the supply chain, the release of the Apple Watch and a mix shift toward the more expensive iPhone 6 Plus. In the long term, they’re also wondering whether Apple Inc. (NASDAQ:AAPL) can push its long term gross margin as close as possible to 40%.

Additionally, they’ll be looking for details on Apple Inc. (NASDAQ:AAPL)’s current channel fill for both the iPhone and Apple Watch so that they can understand the dynamics of the inventory. They also want to learn more about the size of opportunity the Apple Watch offers for the company and early feedback on the device.

Expectations for Apple’s (AAPL) June quarter

Foreign exchange rates are expected to continue weighing on Apple’s results, both in the March and June quarters. Because of weakening currencies, White expects the company to report sales of $49.4 billion for the June quarter, which is significantly higher than the consensus estimate of $46.9 billion the analyst provides.

He’s looking for earnings per share of $1.71 compared to the consensus estimate of $1.69, according to White. He’s expecting Apple to sell 2.77 million units or $1.64 billion in sales. For the full 2015 fiscal year, he’s expecting Apple Inc. (NASDAQ:AAPL) to sell 7.56 million units for sales of $4.5 billion.

Daryanani and his team are expecting revenue of $46.3 billion and earnings of $1.66 per share. The RBC team gives the consensus estimates of $46.5 billion in revenue and earnings of $1.67 per share. They have a price target of $142 per share and an Outperform rating on Apple Inc. (NASDAQ:AAPL).

As of this writing, shares of Apple were up 1.75% to $132.57 per share.