Hippos are semiaquatic creatures known for being among the heaviest animals on the planet.
But not all hippos are the same in build – like individual mammals of other species, hippopotamus weights can vary greatly.
So, how much did the heaviest hippo ever weigh?
The heaviest known hippo weighed in at a massive 9,900 pounds or 4,500 kilograms, according to A-Z Animals.
The hippo was a captive animal at a zoo in Germany, and it’s common for large hippos to be found in zoos and wildlife preserves around the world.
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To put those 9,900 pounds in perspective, it is the equivalent of two John Deere Utility tractors, three Toyota Camrys, or two Honda Pilots.
It’s also the equivalent of 50 average-sized humans.
At 9,900 pounds, the heaviest hippo ever was about twice the weight of an average hippo, which is around 3,300 pounds.
This is taking both males and females into account. The average male hippo weighs between 4,000 and 9,000 pounds or between two tons and 4.5 tons, while the average female hippo weighs between 2,900 and 3,300 pounds or about 1.5 tons.
The average hippo is large in stature, which helps explain its enormous weight. On average, a single hippo’s length falls between 10.8 and 16.5 feet, while the hippo’s height typically reaches between 5 and 6 feet tall.
A full-grown hippo needs a lot of room both on land and in water, which is why zoo enclosures tend to be quite large.
Hippos are indigenous to Africa and are found living near slow-moving bodies of water throughout the continent’s sub-Saharan regions.
Though they have been introduced to ecosystems elsewhere (including South America), hippos as a species are considered to be of vulnerable status and have seen their numbers dwindle over the years.
Like most modern animals, the hippo’s ancestors can be traced back millennia to ancient variants of the species.
Hippopotamus antiquus is the oldest known species of hippo, dating back between one and two million years ago.
Now extinct, fossils of the species indicate it weighed an average of more than three tons, or between 6,000 and 7,040 pounds.
This large ancient hippo is also sometimes referred to as the “Giant Hippo” or the European hippopotamus.
That said, modern hippos are not naturally native to the European continent today.
In addition to hippopotamus antiquus, archeologists have discovered hippo-like reptiles that were even larger and rivaled dinosaurs.
However, they are not believed to be direct ancestors of the modern hippo and therefore have not contributed to its size.
Despite their “fat” appearance, hippos usually are not actually fat. They are naturally bulky and rounded.
Like all mammals, however, a hippo can progress to being overweight if they consume too many calories and do not burn enough energy during the day.
The heaviest hippos on the planet are almost always the result of naturally large frames and more muscular builds rather than excess fat.
Due to their size, hippos can only be weighed on special scales that can withstand the weight.
Hippos in zoos are typically trained to step onto these scales (which are set up as low platforms), which the zookeepers can then switch on to calculate the weight.
It’s worth noting that because hippos in the wild generally cannot be weighed, their average sizes are estimated.
It is, therefore, possible that a hippo heavier than 9,900 pounds has existed in the wild. Nevertheless, this is also unlikely because captive hippos in zoos tend to have more access to food and also receive medical care throughout their lives, giving them the opportunity to grow larger.
There is no current Guinness World Record entry for “heaviest hippo.” However, there are a few “largest” categories in which hippos are named the winner.
These notably include the world’s largest invasive species (the African hippopotamus in the country of Columbia) and the mammal with the largest mouth gape (an average of four feet wide).
According to the San Diego Zoo, the average hippo calf at birth weighs between 50 and 110 pounds (23 and 50 kilograms).
However, there are sometimes those that fall outside this range. Just like humans, hippo weights vary from the moment they’re born.
Hippos mature slowly compared to many other mammals. They reach “adult” maturity between 5 and 7 years old, but they may continue growing in size for years after that.
HippoHaven.com reports that a hippopotamus will continue to grow until they are around 25 years of age, after which they will be considered at their maximum weight (barring any drastic dietary changes).
Due to their large size and bulky appearance, many people wonder how hippos can swim in bodies of water.
In reality, however, hippos actually do not swim at all. They instead hold their breath and walk along the bottom of lakes and rivers until they are ready to get out and simply stroll out the shallow end.
Despite their love of water (hippos can even sleep while submerged), hippos can’t even float. They are too heavy and dense.
Though they may appear to be gentle giants, hippos are considered an extremely dangerous species, particularly when encountered in the wild.
Their thick, durable skin, large tusks, and hefty size make them extremely tough to fend off when attacking.
However, it is occasional aggression and a dislike toward intruders that makes hippos dangerous rather than their size alone.
Hippos like to walk along the bottom of rivers and have been known to attack boats and people.
According to the National Wildlife Federation, hippos are deemed responsible for the deaths of about 3,000 people every year in their natural habitats.
In comparison to other wild animals, hippos are said to cause more human deaths annually than lions, leopards, rhinos, buffalos, and elephants combined.
For as large as regular hippos grow, the pygmy hippo is petite in comparison. This hippopotamus subspecies only reaches a maximum weight that falls between 352 and 605 pounds, or between 10 and six times lighter than a regular hippo.
The pygmy hippo is considered a dwarf species, but unlike many other dwarf animals around the world, it developed naturally in the wild rather than through man-made breeding programs.
Despite the fact that it spends so much time in the water, the hippo is considered the third-largest land-dwelling creature on the planet.
Only the elephant and the rhinoceros beat it in weight, although certain subspecies of rhinos and hippos fall within the same average range.
Still, the hippopotamus is tiny in comparison to the world’s largest and heaviest animal (also the largest mammal), the blue whale.
With a weight that reaches up to 219 tons, the blue whale is five times as heavy as the world’s heaviest hippo.
There are also several varieties of whales that are heavier than hippos in general.
When it comes to the heaviest animals overall, the hippo ranks fifth when all species of whale are grouped together.
The whale shark (encompassing plankton-eating sharks in general) also beats out land-dwelling animals on this list, coming in second behind whales.