Discover The Largest Blue Whale Ever Recorded

Biggest Whale the Blue Whale
© Atomic Roderick/

Written by Hannah Ward

Updated: September 1, 2023

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Of all the animals in the world, both on the land and in the sea, there are none bigger than the blue whale.  This giant cetacean dates back as early as 1.5 million years ago and has roamed the seas for centuries and is bigger than any dinosaur to have ever lived.  They have an average length of 90 feet while weighing over 300,000 pounds with females being slightly larger than males.

But how big was the largest blue whale ever recorded? We’ll analyze the largest blue whales ever discovered and also dive into whether they are the largest species to ever live on Earth!

What do blue whales eat

What do blue whales eat?


The Background on Blue Whales

Blue whales are solitary animals and are usually alone or occasionally in pairs. They don’t form strong bonds other than mother and calf bonds.  Females usually give birth every two or three years and carry their young for twelve months.  Even blue whale calves are huge.

  • As big as an African elephant when born: Blue whale calves are usually around 23 feet long when they are born and weigh 6,000 pounds which is roughly the same weight as an African elephant.  
  • Grow the size of a human every day: Calves gain around 200 pounds per day during their first year, drinking solely their mother’s milk for the first seven months, and usually leave their mother at around a year old.

These giants of the sea are found in every major ocean in the world apart from the Arctic ocean.  Not a lot is known about their location throughout the year but it is believed that some, although not all of them, migrate to new feeding grounds during the summer and back to warmer waters during the winter.  There is an area in the Gulf of California, also known as the Sea of Cortés, that is thought to be a place that is favored by blue whales for calving and nursing between December and March as there has been a number of sightings of females with calves there.

Blue Whale under water with sun light streaming down from the surface above

These huge whales don’t have teeth

©Atomic Roderick/

There are five subspecies of the blue whale – Northern, Southern (Antarctic), Northern Indian, Pygmy, found in the Southern Indian Ocean, and South Pacific.  Blue whales in the southern hemisphere are generally larger than those in the northern hemisphere, and in all subspecies, the females are larger than the males.  However, even the smallest – the Pygmy blue whale – is still one of the largest whales at an average of 79 feet.

Blue whales can also be found off of the Chilean Coast but due to their unique song types, geographic separation, and genetics, they may be a separate subspecies.

How Much Do Blue Whales Eat to Get So Big?

As their name suggests, blue whales have a blue-grey appearance that usually looks blue when they are in the water. Despite their length, their bodies are actually relatively slim and slender, although they have huge, broad heads.  Blue whales are baleen whales which means that they don’t have teeth, instead, they have huge baleen plates that they use to filter krill (small crustaceans) through.  The krill is caught on the baleen plates while the saltwater is sent back out, allowing them to swallow the krill.  As they are so large they need to eat a lot of krill every day to survive and one blue whale can eat 40 million of them per day (around 8,000 pounds).

Blue whales have incredibly long and slender bodies.

©NOAA Photo Library / CC BY 2.0, Flickr – Original / License

A single blue whale can eat more than 40 million krill per day!

Although blue whales can reach a top speed of 30mph in short bursts, they usually travel at 12mph, and when feeding they lunge into clouds of krill at high speed, then slow down to around 3mph as they are filtering the seawater back out. Because of their massive size, it takes a lot of energy for blue whales to slow down and speed up when feeding, so blue whales will often bypass a cloud of krill if it isn’t big enough to be worth their effort to feed on it.

The Largest Blue Whale Ever Recorded

Scientists believe that blue whales are still increasing in size due to the abundance of krill in the Antarctic which means that they’re not short of food.

Blue whales are record breakers when it comes to the size department. The largest blue whale on record weighed 418,878 pounds and the longest blue whale ever recorded was a female that was measured in South Georgia in the South Atlantic in 1909.  This massive whale recorded a whopping length of  110 feet and 17 inches.  

Although no weight was recorded for her, a smaller female from the South Atlantic (90 feet and 6 inches) was weighed in 1947 and tipped the scales at a colossal 418,878 pounds which was far heavier than the average for the species.  Both of these are recorded in the Guinness World Records as the longest mammal and the heaviest animal respectively.

Is the Blue Whale the Largest Whale in the Ocean?

Biggest Animals Ever to Walk the Earth: Blue Whale

Blue whale – a giant of the sea

©Rich Carey/

For more than a million years blue whales have been the largest animal in the world and that’s not about to change anytime soon.  The nearest animal to them in length is the fin whale which averages around 85 feet, although none have ever gotten near the impressive 110 feet of the longest blue whale.  

Scientists believe that blue whales are still increasing in size due to the abundance of krill in the Antarctic which means that they’re not short of food.  Not only that, but marine mammals have gotten much bigger much quicker than land mammals because of the way that the water supports their weight.  This is because of the way the water provides buoyancy, meaning it is much easier for an animal to grow bigger in the sea than it is on land.

With that in mind, it is entirely possible that there are blue whales that are even longer, larger, and heavier than the record breakers that we’ve mentioned, especially considering that it is more than one hundred years since the record was set.  However, one of the most limiting factors in determining if larger blue whales exist is simply that they live in some of the deepest parts of the ocean and are often hundreds of miles away from coastlines, meaning they are often difficult to spot.  Regardless of that, the blue whale’s position as the biggest animal in the world as well as the biggest whale ever looks secure for years to come.

This blue whale mother and calf dwarf the boat

©Chase Dekker/

Is the Blue Whale the Largest Species Ever?

They are believed to be the largest species that have ever lived! That’s an astonishing fact considering that animals ranging from prehistoric insects to sharks, and reptiles have ancient relatives that are significantly larger than today’s species. While the blue whale is the largest species to ever live, here are some past giants from the ocean that were also gigantic.

  • Megalodon: An ancient shark species that hunted whales. Some research points to Megalodon having a maximum weight of 227,510 lbs. More conservative estimates put Megalodon‘s maximum weight at around 50 tons (105,733 lbs). Megalodon went extinct before the blue whale evolved. The absence of these apex predators led to the gigantism found in the largest whales today.
  • Leedsichthys problematicus: Was a prehistoric fish that may have reached 54 feet in length!
  • Finally, an ancient ichthyosaur discovered in England in Somerset, England in 2016 may be the biggest competitor to the blue whale’s size title yet! The species was only recently described, but estimates place its size at up to 85 feet in length!

The Future of the Species

These huge whales have a life expectancy of around 90 years and scientists are able to estimate their age fairly accurately by counting the layers of wax in deceased whales “earplugs”.  These earplugs build up new layers year by year and are known as a reliable method of aging blue whales.  Not only that, but the earplugs can even give great insights into any pollutants that the whales have been exposed to or significant periods of stress that they have been through by the number of hormones present in each layer.

Sadly, despite their numbers once being in the hundreds of thousands, there are now only around 25,000 of these gentle giants left and they are now classed as an endangered species.  Whaling originally significantly damaged their numbers, but despite it now being illegal to hunt blue whales, their numbers continue to fall.  Blue whales don’t have any major natural predators in the wild, although groups of orcas have been known to kill calves and to chase and attempt to kill adults.  Possibly the greatest danger that they face in the water at the moment is the threat of being struck by ships.  Due to their size, blue whales often cannot get out of the way of ships quickly enough, on top of an increase in the speed of modern vessels in already busy shipping lanes.

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About the Author

Hannah is a writer at A-Z animals where her primary focus is on reptiles, marine life, mammals, and geography. Hannah has been writing and researching animals for four years alongside running her family farm. A resident of the UK, Hannah loves riding horses and creating short stories.

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