Blue Whale Size Comparison: Just How Big is the Biggest Animal in the World?

Written by Megan Martin
Updated: March 25, 2023
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Key Points:

  • Blue Whales can grow up to 100 feet (30 meters) in length and weigh up to 200 tons (180 metric tons), making them the largest animals on the planet.
  • Despite their massive size, Blue Whales are still lighter than some of the largest dinosaurs that ever lived. However, when it comes to length, Blue Whales are larger than even the longest dinosaurs, such as the Argentinosaurus.
  • Not only are Blue Whales the largest animals on the planet, but they are also the largest mammals on Earth. Their size is so massive that it’s hard to imagine anything larger.

The Antarctic blue whale is the largest animal in the entire world – but how big is that exactly? In this article, we’ll examine a full blue whale size comparison versus everything from humans to megalodons!

When it comes to something as large as a 10-story building, it can be difficult to wrap your head around. Especially when that “something” is a whale that lives in the ocean you swim and play in.

To help you better understand just why the blue whale is the largest animal in the world, we’ve created images below that compare the blue whale versus some of the largest animals to ever live.

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Types of Blue Whales and Their Sizes

Blue Whale Size Comparison - Blue whale vs. dinaosaur and megalodon
Blue whales are compared to other gigantic animals across history!

The Antarctic blue whale’s size compared to other mammals isn’t just bigger than other land and sea animals – it’s also bigger than other blue whales!

In recent years, there’s been a bit of debate in the science community about what exactly makes a blue whale a blue whale. However, as of now, there are five distinct subspecies of blue whales that are currently recognized, each one the largest animal in the world but still varying in size. These include:

  • Antarctic blue whales (Balaenoptera musculus intermedia)
  • North Atlantic and North Pacific blue whales (Balaenoptera musculus musculus)
  • Pygmy blue whales (Balaenoptera musculus brevicauda)
  • Northern Indian Ocean blue whales (Balaenoptera musculus indica)
  •  South Pacific Ocean blue whales

Of these, the Antarctic blue whales are the largest, being known to weigh around 330,000 pounds or 165 tons. The largest blue whale ever recorded weighed in at 418,878 pounds. Not sure how heavy that is? The entire Statue of Liberty is only around 150 tons!

Blue Whale Vs. Human Size Comparison

Blue Whale Size Comparison - Blue Whale vs human vs megalodon vs dinosaur
Stacking a blue whale vs. sperm whale vs. megalodon vs. brontosaurs vs. human

It’s easy to forget just how big a blue whale is compared to a human until you learn that just the tail of a blue whale is 25 feet wide – nearly 5 times the height of an average human!

If you were to take a blue whale from the ocean and place it onto the average professional baseball field, it would be a little bit longer than the distance from home plate to first base. Humans, on the other hand, are barely taller than the batter’s box is wide.

Some museums even have replica blue whale hearts that visitors can climb through!

And, since blue whales are as long as two school buses (sometimes even longer) they could potentially fit up to 80 people. Although, it might be a bit hard to find a saddle big enough to fit one of these massive sea critters.

Blue Whale Size Comparison to a Megalodon

Megalodon vs. Mosasaurus - Megalodon

Megalodons were the largest


ever. How did they compare to blue whales?

©Herschel Hoffmeyer/

The megalodon was the largest shark to have lived, but how does it measure up to the blue whale?

The answer is “not hardly”.

There’s no doubt that the megalodon was huge. In fact, researchers estimate that they were at least 20 times bigger than the great whites of today, with the potential to be 50 times larger. Being 50 times bigger than a 5,000-pound shark has ensured that the megalodon will also be considered one of the largest animals ever.

But they’re still not quite as large as a blue whale.

The largest megalodon ever would be estimated to be around 250,000 pounds. The smallest adult blue whale usually averages around 290,000 pounds.

Getting a true comparison with such large numbers can be difficult though. After all, with humans only weighing a few hundred pounds, it can be hard to wrap your head around something that weighs the same as thousands of humans.

Since the megalodon has been extinct for millions of years, it can be difficult to get an exact average of how long they are. However, most scientists believe that they could grow to be over 50 feet long, with the longest estimates stretching up to 67 feet. This means that the megalodon is between a school bus and “Uhaul moving truck” shorter than the blue whale.

Blue Whale Size Comparison to a Brontosaurus

Blue Whale Size Comparison - Brontasaurus vs human

A brontosaurus next to a human. Believe it or not, blue whales are even larger than these giant dinosaurs!

©Aunt Spray/

When you think about prehistoric dinosaurs, the brontosaurus might be one of the largest ones that come to mind. After all, these gentle dino giants were known for their long neck, which allowed them to graze on leaves with ease (much like a modern-day giraffe!).

Like the megalodon, we don’t have access to a lot of specific information about the size of the brontosaurus. However, we’ve been able to estimate that they were around 72 feet long and 30,000 pounds (or 15 tons).

The final verdict for this match-up? While it’s a close call in terms of length, it would take around 11 brontosauruses to balance the scale with a single adult male blue whale!

Blue Whale Size Comparison to a Sperm Whale

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

Blue Whale underwater with sunlight streaming down from the surface above

©Atomic Roderick/

The sperm whale is another one of the largest animals in the world. In fact, it’s the largest-toothed predator and even the largest-toothed whale. However, how does it size up compared to the blue whale?

Well, with a maximum length of 60 feet, the largest sperm well barely even comes close to the smallest blue whale. If you were to place them side by side, the sperm whale would be about half the size of the blue whale. This means that nose to nose, the sperm whale’s tail is almost aligned with the blue whale’s front flipper.

Still unsure of just how much bigger the blue whale is compared to their aquatic cousin?

Your average blue whale size comparison to the male sperm whale weighs around 90,000 pounds or around 45 tons. The blue whale, however, can weigh up to 330,000 pounds. So not only are blue whales almost double the size of sperm whales, but they’re also almost triple the weight.

The differences don’t stop there either!

If you were to take a look at a sperm whale’s heart and a blue whale’s heart side by side, you’d find that even the blue whale’s organs are huge compared to the sperm whale’s. The heart of a sperm whale is about 4 feet long and over 270 pounds (the average weight of two humans!).

While that seems ginormous (and it certainly is), it is dwarfed by the blue whale’s heart, which weighs up to 400 pounds and is about the size of a bumper car!

The photo featured at the top of this post is © Maria Spb/

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About the Author

Megan is a writer at A-Z Animals where her primary focus is birds, felines, and sharks. She has been researching and writing about animals for four years, and she holds a Bachelor of Arts in English with minors in biology and professional and technical writing from Wingate University, which she earned in 2022. A resident of North Carolina, Megan is an avid birdwatcher that enjoys spending time with her cats and exploring local zoological parks with her husband.

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