NEW YORK ( TheStreet) -- "It's time to change our perceptions of Apple ( AAPL)," Jim Cramer told the viewers of his "Mad Money" TV show Tuesday. He said that Apple, a stock which he owns for his charitable trust, Action Alerts PLUS , is not only the best technology company, it's also the best retailer. When it comes to comparing retailers, Cramer said the metric to watch is sales per square foot of store space. At the high end of that range is Nordstrom ( JWN), he said, at $434 of sales per square foot. Then there are companies like Whole Foods ( WFMI), which rakes in $875 a square foot. Higher still are high-end retailers like Tiffany ( TIF) at an incredible $1900 a square foot. All of these numbers make Apple, which generates a staggering $4600 a square foot, the undisputed king of retail. Cramer said Apple is more than just a tech company, it not only makes computers and cell phones, it sells music, media, advertising and even fashion. He said Ron Johnson, Apple's senior vice president of retail, is perhaps the finest merchant of our time. He said Apple's earnings are only constrained by how many products it can build. Cramer said it's time to raise his price target on Apple. He now feels the company could earn $22 a share in earnings. Using the average S&P 500 multiple of 14.8 times earnings, that gives Apples a target price of $325 a share.