Nearly half a billion PCs are expected to be sold to consumers in the US up to 2015, fueled by a growing interest in tablet computers, according to a new report by Forrester Research.

According to the ‘The US Consumer PC Market In 2015’ report, PC unit sales across all form factors, desktops, notebooks and laptops, tablets, and netbooks, will increase by 52% over the next five years. The tablet sales in the US will go from 3.5 million units in 2010 to 20.4 million units in 2015, at a compounded annual growth rate of 42%.

The firm said that, starting in 2012, tablets will outsell netbooks, and by 2014, more consumers will use tablets than use netbooks. In 2015, tablets are expected to be represent 23% of the PC unit sales.

Desktop sales may slide over the next five years from 18.7 million units sold in 2010 to 15.7 units in 2015, but will still continue to play a prominent role in the market, buoyed by consumers’ desire for processing-heavy activities such as gaming and watching and editing HD and 3D video and graphics, Forrester said.

By 2015, the firm forecasts the US PC market to account for 42% of notebooks, 23% of tablets, 18% of desktops and 17% of netbooks.

Sarah Rotman Epps, research analyst at Forrester, said: "Tablet growth will come at the expense of netbooks, which have a similar grab-and-go media consumption and Web browsing use case as tablets but don’t synchronise data across services like the iPad does.

"Consumers didn’t ask for tablets. In fact, Forrester’s data shows that the top features consumers say they want in a PC are a complete mismatch with the features of the iPad. But Apple is successfully teaching consumers to want this new device."