A hummingbird's light weight allows him to fly easier since he doesn't need to build up a lot of momentum to get his body off the ground. Hummingbirds can weigh as little as 2.4 grams and as much as 4.5. As a simple comparison, a U.S. penny weighs 2.5 grams and a U.S. nickel weighs 5 grams. Nearly one-third of a hummingbirds weight, or an average of 30 percent, is muscle. A hummingbird's egg weighs 0.4 grams to 1.4 grams; a newly hatched bird is about 1 inch long and 0.62 gram.