How much does the iPhone 6 / iPhone 6 Plus weigh? The new iPhone 6 and even the larger iPhone 6 Plus are both heavier than their predecesor, the iPhone 5S. The iPhone 6 weighs in at 4.55 ounces (129 grams). The iPhone 6 Plus weighs in at 6.07 ounces (172 grams). For comparison, the iPhone 5S weighs 3.95 ounces (112 grams).