How Big is a Blue Whale Really? Size Comparison Guide

Blue whales are really big. But, how big exactly?

It can be hard to wrap your head around just how large they are. So in this guide, I’ll answer common questions and compare it to objects you can related to.

And yes, I will discuss the size of a blue whale’s Johnson.

It’s going to be a fun one.

You’ll see over and over again, in this article and other resources, that blue whales are the biggest animals to have ever lived (as far as we know).

But what does “biggest” mean, exactly?

When you see discussions about “the largest land animal” or “the smallest species of big cat,” what’s really being discussed is the animal’s weight.

Basically, scientists had to agree on weight as the deciding factor on which animals are bigger or smaller.

For example, elephants are considered to be the biggest land animal because of their enormous weight. If scientists went by body length, or height, creatures like giraffes or large pythons would be considered “bigger” than elephants.

So yes, there have been some animals that reached the same length as blue whales, like the genus of dinosaurs Argentinosaurus. But the blue whale is considered “bigger” because it weighs more than any other known animal.

Just thought I’d clear that up from the start.

How Long are Blue Whales?

The largest blue whale ever measured by scientists was 110 feet (33.5 meters) long.

But most are somewhere between 70 and 90 feet in length (21-27 meters).

So, most of the comparisons for length I’ll use in this article will be about 90 feet (27 meters) since that’s about average as far as we know.

How Big is a Blue Whale Compared to a Human?

Length of a blue whale compared to school bus, cars, and baseball bats

A large blue whale can be longer than two standard school buses! That’s just amazing to me.

School buses can seat as many as 40 people. So about 80 people could hang out on a blue whale.

I don’t think the whale would appreciate all those folks invading its space, but they’ve got the room!

They’re longer than 6 midsize passenger cars (about 15 feet/4.5 meters each). The next time you’re stuck at a traffic light, count ahead 6 cars. That’s about how long a blue whale is!

You would have to line up 26 standard baseball bats end to end to equal the length of a blue whale.

Or 15 grown men (6 feet/1.8 meters).

Is Blue Whale bigger than Megalodon?

The exact size of Megalodon is debated. Reports say Megaldon grew up to 60 feet long, so in this case, and you and I know blue whales can grow up to 110 feet.

So yes, a blue whale is bigger than Megalodon.

How Heavy are Blue Whales?

No surprise here, but blue whales are super heavy.

Of course, their length is impressive, but it’s nothing compared to their weight.

They weigh somewhere between 100-150 tons (200,000-300,000 pounds/90,700-136,000 kilograms) as adults.

Keep this in mind, the African bush elephant, the largest living land animal, only weighs 7 tons (14,000 pounds/63,000 kilograms). So an adult blue whale can weigh as much as 14-21 adult African elephants.

I don’t know if you’ve ever stood close to an elephant at the zoo, but I’ve been lucky enough to do so. The idea of a single creature weighing as much as an entire herd of elephants is just crazy.

That’s huge, so huge that it can be hard to wrap your head around it.

Everyday Things that Equal the Weight of a Blue Whale

Weight of a blue whale compared to cars

You’ve got to total up some serious mass to make it weigh as much as a blue whale.

It would take as many as 85 midsize cars to equal all that tonnage.

They weigh as much as 8 large school buses.

Or 1,000 200 pound (90 kilogram) men!

How Big is a Blue Whale’s Heart?

There are some internet sources that state a blue whale’s heart is the size of a small car and that it weighs over 1,300 pounds (590 kilograms).

Don’t get me wrong, a blue whale’s heart is HUGE, but saying that it is the size of a classic Volkswagen Beetle is a gross exaggeration.

Recently, scientists preserved the heart of a 76-foot (23 meters) female blue whale. The poor thing got trapped underneath ice, drowned and her body washed up on the coast of Newfoundland in 2015.

As tragic as this was, it gave scientists the opportunity to dissect the whale and study it. They were able to remove and preserve the whale’s heart, the first time this had ever been done.

The heart only weighed about 400 pounds (181 kilograms). Like I said, huge and really impressive.

But, not the size of 15-foot-long Volkswagen and almost half a ton lighter than some sources claim.

How Big is a Blue Whale’s Heart Compared to a Human?

Size of a blue whales heart

The basic dimensions of the preserved blue whale heart are roughly 5 feet by 4 feet by 5 feet (1.5 meters by 1.2 meters by 1.5 meters).

That gives us a basic volume of 100 cubic feet (2.8 cubic meters).

These aren’t the most precise dimensions since the heart isn’t perfectly rectangular, but it’s a pretty good guesstimate.

100 cubic feet is about the same as the interior of a lot of modern midsize cars.

So you could probably cram 5 or 6 adults inside that space.

Although, I really would not recommend trying to actually have a dinner party inside the heart of a blue whale.

Either it’s a live whale and your presence would not be appreciated.

Or it’s a dead whale and you will never get that stink out of your clothes.

How Big is a Baby (Calf) Blue Whale?

Female blue whales give birth to a single calf every 2-3 years. Calves weigh as much as 3 tons (6,000 pounds/2721 kilograms) when they’re born.

On average, they’re between 23 and 25 feet (7-7.6 meters) long.

Size Comparison of a Blue Whale Calf

Size of a blue whale calf

Baby blue whale calves are the biggest babies in the world.

They are as large as an adult orca when they are born.

Calves outweigh the average American car by over 2,000 pounds and are as long as an ambulance.

Amazingly, they gain about 250 pounds (115 kilograms) a day while they’re nursing. That’s the equivalent of adding adding the mass of a large adult man, someone the size of Dwayne Johnson or Arnold Schwarzenegger, to their weight every day.

How Loud is a Blue Whale?

These giants live pretty solitary lives. They don’t travel together in big groups like some whales do. As adults, blue whales really only gather together for mating.

So when they’re looking for love, they need to be able to communicate across vast amounts of ocean. Otherwise, they might never find each other.

So not only are blue whales the biggest animals, but they are also some of the loudest.

These gentle giants are the second loudest animals on earth. They can produce sounds that are over 188 decibels.

To put that in perspective, jet engines only produce sounds up to 150 decibels.

188 decibels at close range is more than enough to burst your eardrums.

And blue whales’ vocalizations may be heard hundreds of miles/kilometers away; scientists aren’t exactly sure of how far away blue whales can be from each other and still communicate.

But as loud as the blue whale is, there’s another creature that outdoes them.

The sperm whale (Physeter macrocephalus), can produce sounds over 230 decibels, loud enough to stun prey and even inadvertently paralyze a diver’s hand for several hours.

How Fast is a Blue Whale?

Blue whales aren’t exactly breaking any speed records. That makes a lot of sense when you consider just how huge they are.

Their body design is more about long ocean voyages than super speed.

But still, at top speed, blue whales can get up to about 31 miles per hour (50 kilometers per hour), which is pretty respectable.

Their normal traveling speed is somewhere around 12 miles per hour (20 kilometers) and they slow down to about 5 miles per hour (8 kilometers per hour) if they’re feeding.

Speed Comparison

Blue whales are a lot faster than some other cetaceans. The humpback whale (Megaptera novaeangliae) can only reach speeds of about 17 miles per hour (27 kilometers per hour).

The bottlenose dolphin (Tursiops truncatus) can get up to about 17 miles per hour (21 kilometers per hour).

So the blue whale isn’t the speediest thing in the ocean, it’s not the slowest either.

To put it all in perspective in human terms, the world record for Olympic swimming speed was set in 2014 by Florent Manaudou, who’s top speed was somewhere around 5.5 miles per hour (8.8 kilometers per hour).

So a blue whale can swim almost 6 times faster than the best human swimmers in the world.

How Much do Blue Whales Eat?

A LOT!!

But seriously, these guys need an enormous amount of food to keep their bodies going.

Blue whales eat one of the tiniest creatures in the sea, krill.

Krill are tiny crustaceans, similar to shrimp, that school in huge numbers as they eat floating algaes. They are a major food source for large filter feeders like blue whales, fin whales (Balaenoptera physalus) and whale sharks (Rhincodon typus).

Blue whales eat them by scooping up giant mouthfuls of water and filtering it through bristle-like structures in their mouths called baleen.

It’s estimated that blue whales can eat as much as 8,000 pounds (3,600 kilograms) of krill a day.

Weight Comparison of How Much a Blue Whale Eats

OK this one is pretty hard to compare to everyday things since we’re talking about food.

But here goes.

8,000 pounds is roughly equivalent to 32,000 quarter pound hamburger patties.

That’s enough for you to have a hamburger every day for the next 87 years.

Or it’s as much as 12,800 10 ounce steaks. That’s so many steaks that you could have one for dinner every night for 35 years.

Probably not great for your cholesterol, though.

So, what would take you years to eat, a blue whale gulps down in a single day.

How Big is a Blue Whale’s Aorta?

The aorta is the main artery that pumps oxygenated blood throughout the body.

Lots of sources online claim that a blue whale’s aorta is so enormous that an adult human can swim through it.

This is a really cool sounding factoid, but is it true?

Size Comparision: Can You Swim Down a Blue Whales viens?

Human stuck in blue whale aorta

In a word, nope.

Don’t get me wrong, a blue whale’s aorta is enormous. But it is not big enough for a human to swim down.

An adult human could fit their head into a blue’s aorta, but not the rest of their body.

So being able to swim through a whale’s arteries is just as fantastical as it sounds.

How Big is a Blue Whale’s Tongue?

This is something else where you can see some internet exaggeration about these huge beasts.

It’s often quoted that the blue whale’s tongue weighs more than an elephant.

This is true and false. Not all varieties of elephant have the same weight ranges.

It’s thought that a blue whale’s tongue weighs about 8,000 pounds (3,600 kilograms).

It would weigh more than a female Asian elephant. But it would not weigh more than a male elephant, Asian or African (12,000-14,000 pounds/5,400-6,350 kilograms).

So it weighs more than some elephants, but not all of them.

But, 8,000 pounds would be more than twice the weight of the average midsize car (3,500 pounds/1,600 kilograms).

How Wide is a Blue Whale’s Tail Fin?

Size of blue whales tail fin compared to soccer goal

These massive whales need equally impressive tails since that’s how they push themselves through the water.

Their tails are usually around 25 feet (7.5 meters) wide.

That’s more than half the length of a school bus!

From tip to tip, they’re as wide as a professional soccer goal.

How Big is a Blue Whale’s Eye?

Blue whale eye size comparison

The one thing about blue whale’s that’s actually kind of small is their eyes.

A blue whale’s eye is about the size of a small grapefruit or a softball.

This might seem pretty big compared to our own eyes, which are the size of a cherry.

But considering how gigantic a blue whale is, their eyes are kind of puny.

It’s thought that blue whales don’t rely on their sight that much and their small eye size is evidence that their eyesight is pretty weak.

How Big is a Blue Whale’s Poop?

Blue whale poo

Whale poop is probably different that what you’re thinking.

If you’re picturing giant floating poop that looks like a log, you’re way off base.

Whale poop is not really very solid, it’s more like a giant cloud of chunky liquid.

I know, kinda gross.

Since it’s so liquidy, it’s hard to tell exactly how much a whale excretes at a time.

Blue whale poop is bright orange. And I mean bright neon technicolor orange. The color comes from the shells of the krill the whales eat.

Seen from the air, the poop looks like a bright orange cloud in the water, almost as long as the whale itself.

Makes you rethink swimming behind one of these guys.

How Big is a Blue Whale’s Penis?

OK I’m going to do my best to get through this section without making any crude jokes.

But no promises.

Blue whales have the biggest penises in the animal kingdom. Not a huge surprise, given how massive their bodies are.

The biggest penis on record can be found in the Icelandic Phallological Museum in Reykjavik, Iceland.

Yep. An entire museum dedicated to the penis. That is indeed a thing.

But, I digress.

The Phallological Museum has the tip of a blue whale penis on display. The original penis was 16 feet (5 meters) long, was about 12 inches (30 centimeters) around and weighed over 150 pounds (68 kilograms).

Size Comparison of a Blue Whale's Penis

Blue whale's penis size comparison

It’s hard to find an everyday object that has similar dimensions to a blue whale penis. They’re kind of unique.

They’re as long as two midsize cars and they’re about as big around as a large fire hose.

That’s just…er…terrifying? Impressive? Both maybe?

How Big is a Blue Whale’s Vagina?

There are lots of studies about how big a male blue whale’s penis is. They’re huge and really obvious, and frankly, even scientists get distracted by a penis that’s 16 feet (5 meters) long.

But, there really hasn’t been that much research into blue whale vaginas. Or even just whale vaginas in general.

The reason for this is obvious, or rather, that a blue whale’s vagina isn’t that obvious.

When blue whales are mating, the male’s giant penis is pretty darn noticeable.

But there’s really no way to study a whale’s vagina while it’s alive. It’s not exactly like there’s a gynecologist office that can accommodate the biggest animals in the world.

So there just isn’t as much data about blue whale lady parts.

Size Comparison

I think it’s pretty safe to say that a blue whale’s vagina is pretty darn big. They give birth to babies that outweigh the average American car.

You can’t exactly have a tiny vagina if you give birth to young that weigh as much as a full-size sedan.

If I had to venture a guess, I would say that several adult humans could fit inside a blue whale vagina, but I don’t think too many folks are raring to confirm this.

Why are Blue Whales so Big?

One of the reasons whales have evolved to be so big is body heat. The ocean can get pretty darn cold, especially the deep ocean.

The bigger an animal’s body, the more body heat it can generate and hold onto when it’s exposed to cold conditions.

So they can voyage through frigid waters and still thrive.

Also, having a big body can mean that an animal is able to survive longer stretches in between meals.

So if a whale needs to travel great distances to find the next school of krill, its big body, with large fat reserves, can make the trip.

And, for baleen whales, it’s feast or famine. It may be a long time in between meals.

But when they do find a school of krill, it’s enormous. With a bigger body, the whale is better able to catch and eat large quantities of food while it’s available.

Lastly, some scientists also theorize that modern whales evolved to be so large as a means to deal with large predators. There’s a lot of debate about this one, but the basic premise does make sense.

The bigger an animal is, the less likely it is to fall victim to predators.

An adult blue whale is so gigantic that almost nothing can try to kill it and eat it. The only thing in the ocean that has any hope is a large pod of orcas (Orcinus orca).

That is a definite advantage to being the biggest creature in the ocean. If you’re the biggest kid on the block, no one tries to pick on you.

Katherine Morgan

Hey, there! I'm Katherine from Northwest Florida. I've kept aquariums for over two decades, enjoy experimenting with low-tech planted setups and an avid South American cichlid enthusiast.
Katherine Morgan