It's about 10,000 times as heavy as a Grain of Salt.
In other words, 645.5 miligrams is 11,000 times the weight of a Grain of Salt, and the weight of a Grain of Salt is 0.0000909 times that amount.The mass of a grain of salt is approximately 0.0585 mgs. Salt consumption varies widely by country; the people of the United States consume a combined total of about 2,730,000,000,000 miligrams of salt each year.
It's about 2,000 times as heavy as a Poppy Seed.
In other words, 645.5 miligrams is 2,200 times the weight of a Poppy Seed, and the weight of a Poppy Seed is 0.00045 times that amount.(Papaver somniferum)
Fifty percent oil by weight, a poppy seed weighs approximately 0.3 mg. The true pigment of a poppy seed is brown in color, while the characteristic bluish color is an optical illusion caused by a layer of calcium oxalate crystals refracting light rays.
It's about 1,000 times as heavy as a Grain of Sugar.
In other words, 645.5 miligrams is 1,030 times the weight of a Grain of Sugar, and the weight of a Grain of Sugar is 0.000971 times that amount.(a.k.a. white sugar, a.k.a. white refined sugar, a.k.a. table sugar, a.k.a. sucrose, a.k.a. saccharose)
A grain of sugar weighs approximately 0.625 mg. Sugar consumption varies widely by country; the average citizen of the United States consumes about 61,200,000 miligrams of sugar each year.
It's about 200 times as heavy as a Sesame Seed.
In other words, 645.5 miligrams is 177 times the weight of a Sesame Seed, and the weight of a Sesame Seed is 0.00565 times that amount.(Sesamum indicum)
A sesame seed weighs approximately 3.64 mg. The McDonald's Big Mac sandwich, which is well-known for its sesame seed top bun, accounts for the consumption of an estimated 2,010,000,000 miligrams of sesame seeds each day.
It's about 150 times as heavy as a Grain of Sand.
In other words, the weight of a Grain of Sand is 0.0067 times 645.5 miligrams.(medium grain)
With tremendous variety in the size of grain and the component material, grains of sand weigh an average of 4.4 mg. In 2007, a team of seven in Myrtle Beach created the world's tallest sandcastle, which measured 15.10 m (49.55 ft) in height.
It's about twenty times as heavy as a Grain of Rice.
In other words, the weight of a Grain of Rice is 0.045 times 645.5 miligrams.(long grain; 14% moisture content)
A single long grain of rice weighs an average of 29 mg. A staple through most of human history, archaeological evidence indicates that the earliest rice cultivation was about 11,500 years ago.
It's about three times as heavy as a Raindrop.
In other words, the weight of a Raindrop is 0.3 times 645.5 miligrams.(a.k.a. drop, a.k.a. droplet) (average)
The weight of a raindrop depends heavily on the type of weather, but averages about 200 mg. The familiar teardrop shape of a raindrop is actually an optical illusion, caused by the reflection of the light and the motion of the drop.