Loading...

How big is a sperm whale?

🐋 Sperm Whale 🔍 1,300 searches/month ✓ Verified: 2026-02-02

Quick Answer

Sperm whales typically measure 50-60 feet (15-18 meters) in length.

Key Facts

1 Sperm whales have the largest brain of any animal
2 They can reach 18m (60 ft) / 45-60 tons
3 Lifespan: 60-70 years
4 Diet: giant squid, fish, octopus
5 Population: ~300,000 worldwide

How Big Is A Sperm whale?

They can reach 18m (60 ft) / 45-60 tons. Size varies by sex, with males typically larger than females in most species.

AttributeDetails
TypeMarine mammal
FamilyCetacea
HabitatOceans worldwide
ConservationProtected in most countries
Research StatusOngoing scientific study

The Short Answer

Sperm whales (Physeter macrocephalus) are the largest toothed whales and the largest toothed predators ever to exist. Adult males reach impressive lengths of 50-60 feet (15-18 meters) and weigh 35-45 tons (31,750-40,800 kg). Females are considerably smaller at 33-40 feet (10-12 m) and 14-18 tons. Their enormous block-shaped heads can comprise up to one-third of their total body length.

Sperm Whale Size by Sex and Age

Sperm whales exhibit extreme sexual dimorphism—one of the greatest among all cetaceans:

Life StageMale LengthMale WeightFemale LengthFemale Weight
Newborn13 ft (4 m)1 ton13 ft (4 m)1 ton
Juvenile (5 yrs)25 ft (7.6 m)6 tons22 ft (6.7 m)4 tons
Sub-adult (15 yrs)40 ft (12 m)20 tons32 ft (9.8 m)12 tons
Adult50-60 ft (15-18 m)35-45 tons33-40 ft (10-12 m)14-18 tons
Maximum Recorded67 ft (20.5 m)63 tons41 ft (12.5 m)24 tons

Sperm Whale Body Proportions

The sperm whale’s unique body proportions set it apart from all other whales:

Body PartSize/ProportionNotable Feature
Head1/3 of body lengthContains spermaceti organ
Brain17-20 lbs (7.7-9 kg)Largest brain of any animal
Lower Jaw16 ft (5 m) in malesContains 40-52 conical teeth
Teeth4-8 inches (10-20 cm)Weigh up to 2.2 lbs each
BlowholeLeft side of headDistinctive angled blow
Fluke Width15-16 ft (4.5-5 m)Triangular, deeply notched
Dorsal Hump2 ft (0.6 m)Series of ridges behind

According to NOAA Fisheries, the sperm whale’s massive head houses the largest brain of any known animal—five times heavier than a human brain.

Size Comparison: Sperm Whales vs. Other Species

SpeciesLengthWeightHead Size
Sperm Whale (Male)50-60 ft (15-18 m)35-45 tons33% of body
Blue Whale80-100 ft (24-50-60 feet (15-18 meters))150-35-45 tons20% of body
Humpback Whale40-60 ft (12-18 m)25-40 tons25% of body
Orca20-26 ft (6-8 m)3-6 tons20% of body
Giant Squid33-43 ft (10-13 m)440-600 lbsPrimary prey

The Enormous Sperm Whale Head

The sperm whale’s head is its most distinctive feature and deserves special attention:

Head ComponentSizeFunction
Total Head Length16-20 ft (5-6 m)One-third of body
Spermaceti Organ2,000+ gallonsBuoyancy control, echolocation
Melon~500 gallonsSound focusing
JunkMultiple sectionsSound amplification
Nasal PassagesComplex structureClicking sound production

The Smithsonian Institution explains that the spermaceti organ—containing up to 2,000 gallons of waxy oil—helps regulate buoyancy during the whale’s deep dives and may focus their powerful echolocation clicks.

Growth and Development

Sperm whales are slow-growing but long-lived:

Growth MilestoneAgeSize Achieved
Birth013 ft (4 m), 1 ton
Weaning2 years20-23 ft (6-7 m)
Sexual Maturity (F)7-13 years30-35 ft (9-10.7 m)
Sexual Maturity (M)10-12 years36-40 ft (11-12 m)
Physical Maturity (M)50 years50+ ft (15+ m)
Lifespan60-70+ yearsMaximum size

Males continue growing throughout their lives, which is why the oldest males are typically the largest.

Why Are Sperm Whales So Large?

Deep Diving Specialists

Sperm whales dive deeper than almost any mammal—over 7,000 feet (2,100 m). Their large body stores oxygen for dives lasting up to 90 minutes.

Giant Squid Hunters

Their primary prey, giant and colossal squid, are themselves enormous. Large body size and powerful jaws are essential for capturing these deep-sea prey.

Heat Retention

Large bodies maintain temperature better in the frigid deep ocean, where sperm whales spend much of their time hunting.

Spermaceti Buoyancy System

The massive head contains the spermaceti organ, which may help control buoyancy during deep dives. Learn more about why sperm whales got their name.

Frequently Asked Questions

How long is a sperm whale?

Male sperm whales typically measure 50-60 feet (15-18 m), with the largest recorded at 67 feet (20.5 m). Females are smaller at 33-40 feet (10-12 m).

Is the sperm whale the biggest whale?

No, the blue whale is the largest whale at 80-100 feet. However, the sperm whale is the largest toothed whale and the largest toothed predator ever to exist.

How big is a sperm whale compared to a school bus?

A large male sperm whale at 60 feet is about 1.5 times longer than a standard 40-foot school bus, and weighs roughly 3-4 times as much.

Why is the sperm whale’s head so big?

The enormous head houses the spermaceti organ (used for buoyancy and echolocation), the brain, and powerful acoustic equipment for producing the loudest sounds of any animal—up to 230 decibels.

How big is a baby sperm whale?

Newborn sperm whales are already 13 feet (4 m) long and weigh about 1 ton (900 kg). They nurse for 2 years and grow rapidly during this period.

Historical Size Records

During the whaling era, some exceptionally large sperm whales were documented:

RecordMeasurementYearLocation
Longest Male67 ft (20.5 m)1950Antarctic
Heaviest Male63 tons1947Pacific
Largest Head21 ft (6.4 m)UnknownAzores
Heaviest Spermaceti3.5 tons1820sPacific

Modern sperm whales rarely reach these sizes, possibly due to the selective removal of the largest individuals during commercial whaling.

Conservation and Size

Understanding sperm whale size is vital for conservation:

  • Entanglement risk: Large whales encounter more fishing gear
  • Ship strikes: Major threat in shipping lanes
  • Population recovery: Sizes may be returning to pre-whaling norms
  • Climate impacts: Prey distribution changes affect growth

The global sperm whale population is estimated at 300,000-450,000 individuals, recovering after decades of protection from commercial whaling.

Amazing Size Facts

  • A sperm whale’s intestines can be over 300 feet long
  • Their heart weighs about 277 pounds (126 kg)
  • Sperm whales were the inspiration for Moby Dick, though the fictional whale was described as a rare white specimen
  • A single tooth can weigh up to 2.2 pounds and was historically used for scrimshaw
  • The sperm whale’s click is the loudest sound made by any animal—loud enough to stun prey

The sperm whale’s impressive size—especially its massive head—makes it one of the ocean’s most distinctive and awe-inspiring creatures. For more whale size comparisons, explore how big are whales.

🧠

Test Your Knowledge: Sperm Whale

Question 1 of 3

Diet: giant squid, fish, octopus