It's about 0.00000000008 times as heavy as a Hippopotamus
In other words, 0.000000000000000300 megatonnes is 0.0000000000800 times the weight of a Hippopotamus, and the weight of a Hippopotamus is 12,500,000,000 times that amount.(Hippopotamus amphibius) (adult, male)
The average weight of an adult male hippopotamus ranges from 0.000003750 megatonnes. Appearances to the contrary, adult hippos cannot swim or float in water; they actually move by leaping and walking across lake bottoms at about 8 kph (5 mph).
It's about 0.00000000005 times as heavy as an Elephant
In other words, 0.000000000000000300 megatonnes is 0.0000000000500 times the weight of an Elephant, and the weight of an Elephant is 20,000,000,000 times that amount.(for African bush elephant, Loxodonta africana) (Adult, bull)
A bull African bush elephant weighs about 0.00000610 megatonnes. 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 0.00000400 megatonnes
It's about 0.00000000005 times as heavy as a Tyrannosaurus rex
In other words, 0.000000000000000300 megatonnes is 0.0000000000470 times the weight of a Tyrannosaurus rex, and the weight of a Tyrannosaurus rex is 21,000,000,000 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 0.00000640 megatonnes 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 0.00000000003 times as heavy as an Anchor of a Cruise Ship
In other words, 0.000000000000000300 megatonnes is 0.00000000002650 times the weight of an Anchor of a Cruise Ship, and the weight of an Anchor of a Cruise Ship is 37,700,000,000 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 0.00001130 megatonnes. 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 0.000000000004 times as heavy as The Space Shuttle
In other words, 0.000000000000000300 megatonnes is 0.00000000000420 times the weight of The Space Shuttle, and the weight of The Space Shuttle is 240,000,000,000 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 0.0000710 megatonnes. The shuttle's spacious cargo bay carried the Chandra X-ray Observatory into orbit in 1999 — a payload that weighed 0.0000200 megatonnes.
It's about 0.000000000003 times as heavy as a Blue Whale
In other words, 0.000000000000000300 megatonnes is 0.000000000002870 times the weight of a Blue Whale, and the weight of a Blue Whale is 348,000,000,000 times that amount.(Balaenoptera musculus)
Blue whales weigh between 0.000105 megatonnes. The largest mammal to have ever lived, blue whales feed almost exclusively on krill — tiny invertebrates weighing about 0.000000000001000 megatonnes each.
It's about 0.000000000002 times as heavy as a House
In other words, 0.000000000000000300 megatonnes is 0.000000000001920 times the weight of a House, and the weight of a House is 521,000,000,000 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 0.000156 megatonnes, 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 0.000000460 megatonnes.