Critter Factbook

Animals · Whales

Blue whales: how big they get, what they eat, how long they live, and more

Each answer below is one line in our words, with the scope the source was writing about and the source’s own sentence further down.

Quick answers

QuestionAnswerScopeSourceChecked
How much they weigh Up to about 330,000 pounds, in the Antarctic. North Atlantic and North Pacific blue whales are smaller, at over 100,000 pounds. Blue whales; figures differ by ocean NOAA Fisheries
How long they get Up to about 110 feet in the Antarctic and about 90 feet in the North Atlantic and North Pacific. Blue whales; figures differ by ocean NOAA Fisheries
What they eat Krill, almost nothing else. The biggest whales may eat up to 6 tons of it a day. Blue whales NOAA Fisheries
How long they live An estimated 80 to 90 years. Blue whales NOAA Fisheries
How fast they swim About 5 mph normally, with short bursts above 20 mph. Blue whales NOAA Fisheries
Where they live Every ocean except the Arctic. Blue whales NOAA Fisheries
How long pregnancy lasts About 10 to 12 months, by NOAA's current estimate. Blue whales NOAA Fisheries
When they can breed Thought to be between 5 and 15 years of age. Blue whales NOAA Fisheries

In the sources’ own words

How much they weigh

“…blue whales can grow up to about 90 feet and are over 100,000 pounds, but in the Antarctic, they can reach up to about 110 feet and weigh more than 330,000 pounds.”

NOAA Fisheries, Blue Whale

Scope: Blue whales; figures differ by ocean

How long they get

“…blue whales can grow up to about 90 feet and are over 100,000 pounds, but in the Antarctic, they can reach up to about 110 feet and weigh more than 330,000 pounds.”

NOAA Fisheries, Blue Whale

Scope: Blue whales; figures differ by ocean

What they eat

“They feed almost exclusively on krill…”

“Some of the biggest individuals may eat up to 6 tons of krill a day.”

NOAA Fisheries, Blue Whale

Scope: Blue whales

How long they live

“Lifespan Estimated at around 80 to 90 years…”

NOAA Fisheries, Blue Whale

Scope: Blue whales

How fast they swim

“…typically swim at about 5 miles an hour…”

“…can accelerate to more than 20 miles an hour for short bursts…”

NOAA Fisheries, Blue Whale

Scope: Blue whales

Where they live

“Blue whales are found in all oceans except the Arctic Ocean.”

NOAA Fisheries, Blue Whale

Scope: Blue whales

How long pregnancy lasts

“…the gestation period is approximately 10 to 12 months.”

NOAA Fisheries, Blue Whale

Scope: Blue whales

When they can breed

“The age of sexual maturity is thought to be 5 to 15 years.”

NOAA Fisheries, Blue Whale

Scope: Blue whales

What these sources do not say

  • An exact record weight. NOAA gives rounded upper figures, and says scientists know little about blue whale life history.
  • How the five subspecies differ in size, beyond the ocean-by-ocean figures above.

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