It's about one-fifteen-thousandth as heavy as a Dachshund.
In other words, the weight of a Dachshund is 10,000 times 645.5 miligrams.(a.k.a. "Wiener dog", a.k.a. Teckel, a.k.a. Dackel, a.k.a. "hot dog dog", a.k.a. "sausage dog", a.k.a. "doxie") (FCI standard; standard size)
It's about one-twenty-thousandth as heavy as a Gold Bar.
In other words, 645.5 miligrams is 0.00005188326728 times the weight of a Gold Bar, and the weight of a Gold Bar is 19,274.03674 times that amount.(London Good Delivery bar)
It's about one-forty-five-thousandth as heavy as a Dalmatian.
In other words, the weight of a Dalmatian is 45,700 times 645.5 miligrams.(a.k.a. Dalmatinac, a.k.a. Carriage Dog, a.k.a. Spotted Coach Dog, a.k.a. Firehouse Dog) (FCI standard; male)
It's about one-seventy-thousandth as heavy as a Toilet.
In other words, 645.5 miligrams is 0.0000148 times the weight of a Toilet, and the weight of a Toilet is 67,600 times that amount.(KOHLER Round front sitting flush toilet, model #K-11471-0)
The weight of a typical round front sitting flush toilet is 43,600,000 miligrams. The Indian town of Musiri in Tamil Nadu state features the world's only paying toilet, which rewards its users up to 10¢ Indian (10 paisas) per visit and uses the waste for compost and fertilizer.
It's about one-seventy-five-thousandth as heavy as an Octopus.
In other words, the weight of an Octopus is 77,000 times 645.5 miligrams.(for Giant Pacific Octopus, Enteroctopus) (Adult, average)
It's about one-one-hundred-fifty-thousandth as heavy as a Kangaroo.
In other words, the weight of a Kangaroo is 130,000 times 645.5 miligrams.(for red kangaroo, Macropus rufus) (adult, male)
It's about one-two-hundred-fifty-thousandth as heavy as a Panda Bear.
In other words, the weight of a Panda Bear is 230,000 times 645.5 miligrams.(a.k.a. Giant Panda, Ailuropoda melanoleuca)(Adult, male)
An adult, male Giant Panda weighs up to 150,000,000 miligrams. Despite having the digestive system of a carnivore, the panda eats only bamboo and must eat up to 6,400,000 miligrams of it per day to compensate for the limited energy the plant provides.