It's about one-three-hundred-thousandth as heavy as an Elephant
In other words, 0.021 kilograms is 0.00000350 times the weight of an Elephant, and the weight of an Elephant is 290,000 times that amount.(for African bush elephant, Loxodonta africana) (Adult, bull)
A bull African bush elephant weighs about 6,100 kg. Among African elephants, both males and females have tusks (whereas female Asian elephants, Elephas maximus, do not have tusks) which can grow to 3 m (10 ft) and typically weigh about 4,000 kg
It's about one-three-hundred-thousandth as heavy as a Tyrannosaurus rex
In other words, 0.021 kilograms is 0.00000330 times the weight of a Tyrannosaurus rex, and the weight of a Tyrannosaurus rex is 300,000 times that amount.(for FMNH PR2081, a.k.a. "Sue") (a.k.a. Tyrannosaurus, a.k.a. T-Rex) (estimated live weight)
The notable Tyrannosaurus specimen housed at the Field Museum of Natural History in Chicago, Illinois, "Sue," is estimated to have weighed about 6,400 kilograms while alive. A renowned predator in popular culture, the teeth of tyrannosaurus rex were up to 33.02 cm (13 in) long.
It's about 350,000 times as heavy as a Grain of Salt
In other words, 0.021 kilograms is 359,000 times the weight of a Grain of Salt, and the weight of a Grain of Salt is 0.000002790 times that amount.The mass of a grain of salt is approximately 0.00000005850 kilograms. Salt consumption varies widely by country; the people of the United States consume a combined total of about 57,000,000 kilograms of salt each year.
It's about one-five-hundred-fifty-thousandth as heavy as an Anchor of a Cruise Ship
In other words, 0.021 kilograms is 0.000001860 times the weight of an Anchor of a Cruise Ship, and the weight of an Anchor of a Cruise Ship is 538,000 times that amount.(for QE2 forward anchor, a.k.a. RMS Queen Elizabeth 2)
Each of the forward anchors of the RMS Queen Elizabeth 2 weighs 11,300 kg. The anchor of the QE2 now sits in front of the Holyrood Church in Southampton, England, United Kingdom, along a pedestrian tourist route known as "the QE2 mile."
It's about 0.0000003 times as heavy as The Space Shuttle
In other words, 0.021 kilograms is 0.000000300 times the weight of The Space Shuttle, and the weight of The Space Shuttle is 3,300,000 times that amount.(for Endeavour, a.k.a. OV-105, a.k.a. Orbiter Vehicle-105) (empty weight, excluding main engines)
When empty, the space shuttle Endeavour weighs 71,000 kilograms. The shuttle's spacious cargo bay carried the Chandra X-ray Observatory into orbit in 1999 — a payload that weighed 19,737 kg.
It's about 0.0000002 times as heavy as a Blue Whale
In other words, 0.021 kilograms is 0.0000002010 times the weight of a Blue Whale, and the weight of a Blue Whale is 4,980,000 times that amount.(Balaenoptera musculus)
Blue whales weigh between 73,000 and 136,000 kg. The largest mammal to have ever lived, blue whales feed almost exclusively on krill — tiny invertebrates weighing about 0.001 kilograms each.
It's about 0.0000002 times as heavy as a House
In other words, 0.021 kilograms is 0.0000001350 times the weight of a House, and the weight of a House is 7,410,000 times that amount.(149 sq. m, single-level, unfurnished)
A 149 sq. m (1,600 sq. ft), single-story, unfurnished house (without extensive masonry) of the type commonly found in America would weigh approximately 156,000 kg, based on the weight of the included materials. In contrast, a yurt — a type of dwelling structure popular among nomadic peoples of East Asia — typically weighs less than 458 kg.