For the quarter ended in September, Apple set revenue records for iPhone and wearables and all-time quarterly records for services and Mac, but warned that said sales for the holiday quarter could miss expectations.

The company posted quarterly revenue of $62.9 billion, an increase of 20 percent from the year-ago quarter, and quarterly earnings per diluted share of $2.91, up 41 percent. Apple said that international sales accounted for 61 percent of the quarter’s revenue.

The company sold 46.9 million iPhones in the fiscal fourth quarter, and the average selling price (ASP) of iPhones was $793. A higher ASP means customers purchased more high-end handsets such as the iPhone X and the newer XS and XS Max, versus less expensive models like the older iPhone 8 and iPhone 7.

During Apple’s investors call, executives said they will no longer be providing unit numbers for iPhone, iPad and Mac, removing a key metric for investors to track device demand. Apple CFO Luca Maestri explained the change saying that unit sales don’t provide a clear picture of the company performance.

Apple's services revenue, which includes iCloud, the App Store and Apple Music, reached an all-time high of $10 billion. Excluding a one-time favorable adjustment of $640 million recognized in the fourth quarter of fiscal 2017, services revenue grew from $7.9 billion in the fourth quarter of fiscal 2017 to $10 billion in the fourth quarter of fiscal 2018, an increase of 27 percent.

"We’re thrilled to report another record-breaking quarter that caps a tremendous fiscal 2018, the year in which we shipped our 2 billionth iOS device, celebrated the 10th anniversary of the App Store and achieved the strongest revenue and earnings in Apple’s history," said Tim Cook, Apple’s CEO. "Over the past two months, we’ve delivered huge advancements for our customers through new versions of iPhone, Apple Watch, iPad and Mac as well as our four operating systems, and we enter the holiday season with our strongest lineup of products and services ever."

Apple said it expects between $89 billion and $93 billion in revenue for its fiscal first quarter ending in December.

According to Tim Cook, said some of the forecast was explained by Apple releasing its top-end iPhone models, the XS and XS Max, in the fiscal fourth quarter. Cook also said foreign exchange rates would have a $2 billion negative impact on Apple’s sales forecast. In addition, Cook was
unsure whether Apple can make enough new iPhones, Apple Watches, iPads and Mac models it released in recent weeks. He also said that Apple is "seeing some macroeconomic weakness in some of the emerging markets," without specifying which ones.

However, Apple CEO stressed that Apple was happy with its performance in China, where revenue grew 16 percent to $11.4 billion, the fifth quarter in a row the company has had double-digit growth in the region.