How Much Does a Whale Shark Weigh?

Adult whale sharks typically weigh between 9-12 tons (18,000-24,000 pounds), with the largest individuals weighing up to 20 tons (40,000 pounds). This makes whale sharks the heaviest fish species on Earth. Despite their name, whale sharks are not whales - they are filter-feeding sharks and therefore fish, not mammals.

Quick Facts

Attribute	Details
Type	Marine fish
Family	Rhincodontidae
Habitat	Oceans worldwide
Conservation	Protected in most countries
Research Status	Ongoing scientific study

Important: Whale Sharks Are Fish, Not Whales

Characteristic	Whale Shark	Whales
Classification	Fish (Chondrichthyes)	Mammals (Cetacea)
Breathing	Gills (extract oxygen from water)	Lungs (breathe air)
Body temperature	Cold-blooded	Warm-blooded
Skeleton	Cartilage	Bone
Maximum weight	20 tons	substantial weight (blue whale)

Whale Shark Weight Statistics

Measurement	Weight	Notes
Average adult	9-12 tons (18,000-24,000 lbs)	Most commonly observed
Large adult	12-15 tons (24,000-30,000 lbs)	Above average
Maximum recorded	20+ tons (40,000+ lbs)	Exceptional individuals
Newborn	~1 kg (2.2 lbs)	Extremely small at birth
Juvenile (3m long)	100-200 kg (220-440 lbs)	Growing rapidly

Weight by Size

Whale shark weight correlates with length:

Length	Estimated Weight	Life Stage
0.5 m (1.6 ft)	~1 kg (2.2 lbs)	Newborn
3 m (10 ft)	150-300 kg (330-660 lbs)	Young juvenile
6 m (20 ft)	1-2 tons	Juvenile
9 m (30 ft)	6-8 tons	Sub-adult
12 m (40 ft)	10-14 tons	Adult
15 m (50 ft)	15-18 tons	Large adult
18 m (60 ft)	18-20+ tons	Maximum size

Weight Comparison with Other Marine Animals

Species	Type	Maximum Weight
Blue whale	Mammal	varies by species
Humpback whale	Mammal	40 tons
Whale shark	Fish	20 tons
Orca	Mammal (dolphin family)	6 tons
Basking shark	Fish	5 tons
Great white shark	Fish	2.3 tons
Ocean sunfish	Fish	2.3 tons

Weight Comparison with Other Sharks

Shark Species	Maximum Weight	Maximum Length
Whale shark	20 tons	18.8 m (61.7 ft)
Basking shark	5 tons	12 m (40 ft)
Great white shark	2.3 tons	6 m (20 ft)
Tiger shark	900 kg (2,000 lbs)	5.5 m (18 ft)
Hammerhead shark	450 kg (1,000 lbs)	4.5 m (15 ft)
Bull shark	315 kg (700 lbs)	3.5 m (11.5 ft)

Why Are Whale Sharks So Heavy?

Factor	Contribution
Massive length	Up to 18.8 m (61.7 ft) long
Thick body	Wide, cylindrical body shape
Large liver	Oil-filled liver provides buoyancy
Cartilage skeleton	Lighter than bone but still substantial
Muscle mass	Powerful swimming muscles
Water in gills	Large gill capacity for filter feeding

Body Part Weight Estimates

Body Part	Estimated Weight	Notes
Liver	1-2 tons	15-20% of body weight, oil-rich
Skin	500-800 kg	Up to 10 cm (4 in) thick
Fins (total)	200-400 kg	Pectoral fins up to 1.5 m each
Head	1-2 tons	Includes massive mouth

Weight Through Growth Stages

Life Stage	Age	Length	Weight
Newborn	Birth	40-60 cm	~1 kg
Juvenile	1-5 years	1.5-4 m	50-500 kg
Sub-adult	5-15 years	4-8 m	0.5-4 tons
Young adult	15-25 years	8-10 m	4-8 tons
Mature adult	25-50 years	10-14 m	8-15 tons
Old adult	50+ years	14-18 m	15-20 tons

How Do Scientists Weigh Whale Sharks?

Method	Description	Accuracy
Direct weighing	Rare, only possible with stranded/captured sharks	Highest
Length-weight formulas	Mathematical calculations based on measurements	High
Photogrammetry	Measuring body volume from photos	Moderate-High
Displacement	Measuring water displacement	Moderate
Visual estimation	Experienced observer estimates	Low

Whale Shark Diet and Weight

Despite their enormous size, whale sharks eat tiny prey:

Feeding Metric	Value
Primary food	Plankton, fish eggs, small fish
Daily food intake	20-30 kg (45-65 lbs)
Food as % of body weight	0.2-0.3% daily
Comparison (lion)	Lions eat 5-7% of body weight

Their filter-feeding lifestyle requires constant eating of small prey rather than large meals.

Frequently Asked Questions

Are whale sharks heavier than great white sharks?

Yes, dramatically so. Whale sharks can weigh up to 20 tons (40,000 lbs), while great white sharks max out at about 2.3 tons (5,000 lbs). The average whale shark is 4-5 times heavier than the largest great white.

How does a whale shark’s weight compare to a blue whale?

Blue whales are much heavier than whale sharks. A large blue whale at substantial weight weighs nearly 10 times more than the heaviest whale shark (20 tons). This is because blue whales are mammals with dense bones and massive blubber stores, while whale sharks have lighter cartilage skeletons.

Why are baby whale sharks so small compared to adults?

Newborn whale sharks weigh only about 1 kg (2.2 lbs) and measure 40-60 cm, making them roughly 20,000 times lighter than maximum-size adults. This enormous growth factor is possible because whale sharks grow slowly over 70-130 years.

Do whale sharks gain weight seasonally?

Whale sharks likely experience weight fluctuations based on food availability. They may gain weight when following plankton blooms or fish spawning events and lose weight during periods of migration or reduced food availability.

How much would a whale shark weigh on land?

A whale shark would weigh the same on land, but without water’s buoyancy, it would be crushed by its own weight. Water supports about 800 times more weight than air, which is why whale sharks (and whales) can grow so large in the ocean.

Conservation Implications

The whale shark’s large size affects its conservation status:

Size-Related Factor	Conservation Impact
Slow growth	Takes 25-30 years to reach maturity
Large body	Valuable for fishing (meat, fins, oil)
Surface feeding	Vulnerable to boat strikes
Visibility	Easy to spot and target

Related Questions

• How big do whale sharks get?
• Is a whale shark, a fish?
• What does a whale shark eat?
• Why are whale sharks endangered?