How much does ET weigh?

Answer 1

Despite his size, E.T. weighs a mere 35 pounds, confirmed by the scene where Elliott sets E.T. on the bathroom scale. Even Elliott expresses his disbelief at this seemingly low weight. Later in the scene, E. T. is shown completely submerged in the bathtub, a feat that would not be easily possible based on his apparent density. Certainly, E.T. is able to manipulate his own measured weight (or at the very least reduce it) based on his telekenetic abilities. He can make 4 fully loaded bicycles fly, after all.

So, perhaps a better question would be, "What is E.T.'s mass?" Since it is never properly measured in the movie, we may never know. Personally, I would estimate E.T.'s actual mass to be slightly higher than the mass of an amount of water equal to E.T.'s volume based on the following evidence: 1) He sinks, so he is likely heavier than water.

2) When he is in a state where he is unconcious and not able to affect gravity (such as when he is found in the culvert or when he is "dead"), people don't seem to have trouble lifting him, so he's likely no heavier than a person of similar size. So based on these observations, I'd estimate E.T.'s mass at between 25kg and 30kg, or between 55 and 65 lbs.