Apple Inc. (NASDAQ:AAPL) shares edged upward by more than 1% today after RBC Capital Markets analysts said they see a tremendous amount of upside potential for the company thanks to the upcoming iPhone 6.

Apple Gold iPhone 6

Estimating iPhone 6 sales

Analyst Amit Daryanani said in his latest report that he is currently estimating that Apple will sell 56 million iPhones in the December quarter. However, he thinks that estimate might prove conservative, suggesting that the company could even ship over 70 million units in that quarter.

The reason Daryanani thinks his estimate will come up short is because of data he reportedly got from Apple’s supply chain. The analyst said the data suggests Apple may have ordered up to 80 million iPhone 6 units to be delivered by the end of the year. He said the orders appear to be in two sizes, as expected: 4.7 inches and 5.5 inches. Last year Apple had told its supply chain to produce 60 million units for the end of the year.

The analyst suggests that Apple could sell about 10 million iPhone 6 handsets over launch weekend and hit 15 million by the end of the September quarter. It’s expected that Apple will show off the iPhone 6 on Sept. 9 and then possibly launch it on Sept. 19.

iPhone 6 sales to ramp up for December

Then in the December quarter, Daryanani estimates that Apple could sell up to 60 million iPhone 6 units, thus hitting up to 75 million units by the end of the current calendar year. Unsurprisingly, last year’s December quarter was the biggest iPhone quarter ever, as Apple set a new record of 51 million iPhones.

The RBC Capital analyst and others have said they expect this year’s iPhone sales to rise significantly because the iPhone 6 is expected to have a bigger display. He maintained his $110 price target and Outperform rating for Apple in his latest report. Last week the analyst raised his price target for the company from $100 to $110 per share.