Multiple choice general knowledge science & technology Whats the weight of a brain 1.4Kg 4 lb 3 lb 3.2 lb Reveal answer Fill a bubble to check yourself A,C Correct answer Explanation The average adult human brain weighs approximately 1.4 kg (about 3.1 lbs). Both values represent the same physical weight in different units - 1.4 kg equals roughly 3 pounds.