The new iPad Mini (pictured) measures 7.9 inches long, 5.3 inches wide and is 0.29 of an inch thick. Only slightly larger is the Kindle Fire HDX, which measures 9.1 inches long and 6.2 inches wide. In other words, Amazon's unit is an inch longer and an inch wider than Apple's. Thickness is a wash. At 0.31 of an inch, Kindle Fire HDX is just 0.02 of an inch fatter. The iPad mini with Wi-Fi and LTE radios tips the scales at an even 12 ounces. Similarly equipped, Kindle Fire HDX weighs just 1.5 ounces more at 13.5 ounces.