The blue whale · its heart

A blue whale’s heart can beat twice a minute

A suction-cup tag first recorded a blue whale’s heartbeat in 2018: sometimes as slow as 2 beats a minute in a dive, up to 37 at the surface. The heart preserved in Toronto was weighed at 175 kilograms and is about a metre wide: huge, and far smaller than the car it is often compared to.

2beats a minute at the lowest reading of the first tagged whale (PNAS, 2019)
175 kgweight of the heart preserved at the Royal Ontario Museum, Toronto
20–23 cmreported diameter of the aorta, the main artery; press accounts say a head fits

See it next to you

Two blue whales at the surface seen from above; one breathes out a tall blow of spray. — Two blue whales in the Channel Islands National Marine Sanctuary, California, seen from the air. Photograph: NOAA National Marine Sanctuaries, public domain.

Stand next to it

Enter your height. The heart, the aorta and two cars are drawn to the same scale as you.

Your height, in centimetres

How much to show

Average people

Compare with

you
dashed: an average adult man (176 cm) and a child of 8 (130 cm)
the heart, at the width and length of the preserved specimen
the aorta, at the two reported widths, with your hand inside
a car, as a box the size of its outline

You: 135 cm
The heart, top to bottom: 106 cm29 cm shorter than you
The car: Volkswagen Beetle 4.1 m4 hearts end to end cover its length

The heart in the picture belonged to a mature female about 23 m long that washed ashore in western Newfoundland in 2014, one of nine blue whales that died in the ice of the Gulf of St. Lawrence in March 2014. Staff of the Royal Ontario Museum in Toronto weighed the heart at 175 kg, then had it preserved in Germany by replacing its water with silicone. The finished specimen is 96 cm wide and 106 cm long. The outline on the stage is drawn to those two measurements; it shows the shape in plan view, not a tracing of the specimen.

For years the heart was said to be as big as a car. Mark Engstrom of the Royal Ontario Museum said in 2015: “It’s big, but it’s smaller than people have suggested — not quite as big as a Volkswagen.” Set end to end, 4 hearts cover a Beetle’s 4.1 m, and the heart’s 175 kg is about a fifth of the car’s 730–930 kg.

The mounted skeleton of a pygmy blue whale in a museum hall, seen from the side: a long curved spine, ribs like a cage and a narrow skull at the right. — The bar on the stage is the length of the museum’s whale. This mounted skeleton, of a pygmy blue whale that stranded in Victoria, Australia, in 1992, stands in Melbourne Museum. The panorama is stitched from three photographs, so the outline bends.Jeffrey from Christchurch, New Zealand, CC BY-SA 2.0, Wikimedia Commons

Could a child swim through the aorta?

The aorta is the artery that leaves the heart. Press accounts of the museum’s work say it would take a human head, not a body. Your hand and your shoulders, at the reported width:

Widths of the body, in centimetres, against the reported aorta (20 to 23 cm)
Body part	Average width	Against 20–23 cm
Head, two-year-olds, width	13.3	Narrower
Head, eight-year-olds, width	14.1	Narrower
Head, adult men, width	15.4	Narrower
Head, adult men, front to back	20.0	About the same as the narrower report
Shoulders, two-year-olds	23.9	Wider
Shoulders, eight-year-olds	31.4	Wider
Shoulders, adult men	51.0	Wider

Survey averages: children from a 1977 US survey, men from ANSUR II (2012). Shoulder width is the survey’s shoulder-breadth measure. Across the collarbones, two-year-olds average 21.2 cm, inside the reported range; shoulders can also be turned and squeezed.

No measured diameter for this heart’s aorta appears in the sources read for this page. The range comes from two older reports. One is a 1959 dissection of a large whale whose heart weighed 116 kg: its aorta was 20 cm across, and the abstract does not name the species. The other is a 2001 teaching sheet from a marine centre in California, which says 9 inches (23 cm) and warns that it uses fin whale figures where blue whale figures are missing. The 1959 figure comes from a dissection and the teaching sheet gives no method. Neither could show the living width: in the fin whale the arch swells with blood pressure, so a living arch may be wider.

Studies of the fin whale, a smaller whale, give an outside diameter of about 12 cm for the descending aorta, and an arch whose inner radius, at an estimated mean blood pressure, is 2.5 times that of the descending aorta. So the living arch of a blue whale may be wider than either report. Even so, nothing in the sources supports a child swimming through it: a two-year-old’s shoulders average 23.9 cm across.

From a child’s heart to a whale’s

Drag from the heart of an eight-year-old towards the heaviest blue whale heart weighed by whalers. The Toronto heart weighs about 1,300 times as much as a child’s and about 530 times as much as a man’s.

A child’s heartThe heaviest weighed by whalers (750 kg)

The blue whale heart in Toronto

Mass: —
Volume of muscle: —
Compared with a child’s: —
Share of the car’s mass: —

Heart muscle weighs 1.05 kg to the litre, a value measured in children’s hearts and used here for every size, so the volume follows the mass.

Seven hearts, from small to large
Heart	Mass	Volume of muscle	How it is known
A child of 8	135 g	130 ml	About 130 g, calculated: a published formula for autopsy heart weight, applied to the average size of an 8-year-old (plus or minus 20 %).
An adult woman	245 g	230 ml	245 g, the average heart weight of 102 women aged 18 to 35, weighed at autopsy.
An adult man	330 g	320 ml	331 g, the average heart weight of 232 men aged 18 to 35, weighed at autopsy.
An African elephant	16 kg	15 l	12 to 21 kg, for an elephant of 4 to 5 tonnes; the mark on the scale sits at the middle.
The blue whale heart in Toronto	175 kg	167 l	175 kg, from the Royal Ontario Museum’s paper; it does not say at which stage it was weighed.
The average of 32 blue whales weighed by whalers	347 kg	330 l	347 kg, the average of 32 blue whales weighed piece by piece in the Antarctic in 1947–49 (the lightest heart was 112 kg).
The heaviest of 32 weighed by whalers	750 kg	714 l	750 kg, the heaviest of those 32.

Here heart muscle is counted at the same density at every size, so the volume follows the mass: 175 kg of muscle is about 167 litres, 88 % of a 189-litre drum, the size the museum’s team used for its preserving fluid. A car has no such simple volume, because the box around it is mostly air, so the car is compared by mass: 175 kg against 730 to 930 kg for a Beetle.

The Toronto heart is a single specimen, from a decomposing whale that spent a year in a freezer before it was preserved. The paper gives its weight without saying whether it was weighed fresh, frozen or thawed; press reports give about 180 kg and 199.5 kg for the same heart. It is not the only blue whale heart ever weighed. In the Antarctic in 1947–49 whalers cut 32 blue whales into blocks on the decks of factory ships and weighed every part (Nishiwaki, 1950). Their hearts weighed 112 to 750 kg, 347 kg on average, without the blood that flowed away. The Toronto heart lies inside that range, near its light end, and equations for mammals predict 319 kg for a whale of 70,000 kg, close to the whalers’ average.

The Toronto whale itself was never weighed. The 2019 paper assumes 70,000 kg for a whale of 23 m, and interpolating between the masses that the 2026 study estimates for its tagged whales (22.2 and 24.3 m) gives roughly 78,000 kg; with those estimated masses the heart is about 0.22 to 0.25 % of its body. A man’s heart is about 0.43 % of his (331 g in men averaging 76 kg).

Blood pushed out by one beat
Heart	Blood per beat	Source
A child of 8	about 45 ml	MRI, left ventricle
An adult	87–108 ml	MRI, women and men
A blue whale of 70 tonnes	about 80 litres	prediction from mammal equations, not measured

The whale’s 80 litres is about 1,800 times the child’s. Guinness World Records gives about 220 litres (58 US gallons) and NOAA 60 gallons; none of the sources read explains how that was worked out.

A grey-brown heart of a sei whale on a stand in a glass case, with the stumps of its large vessels at the top. — The heart of a sei whale, a smaller baleen whale, in the Kulturama museum, Zürich. No open-licence photograph of a blue whale heart was found, so the closest relative is shown.Tiia Monto, CC BY-SA 3.0, Wikimedia Commons

How it beats

Choose a moment in a dive and press play. Each thump is made by this page at rates taken from the studies: the tags recorded the heart’s electrical signal, not a sound. A lunge is the moment the whale surges forward with its mouth open to gulp water and prey.

A moment in the dive

Volume

Made by this page, not recorded from a whale. The rates come from the studies. The gap between the two thumps is a timing choice, set to 1.0 s, the QT interval (how long the heart’s lower chambers take to excite and relax electrically) recorded at 32 beats a minute; nobody measured the gap between the sounds. The pitch and the shape of the sound are invented.

Lowest reading: 2 a minute, one beat every 30 seconds. The lowest instantaneous rate recorded during a dive in the first paper (2019), from one whale.
Gliding at depth: 6 a minute, one beat every 10 seconds. Typical rate at the bottom of a dive in the first paper: 4 to 8. A curve fitted to five more whales in 2026 gives 7.7 a minute, one minute after a lunge.
Just after a lunge: 22 a minute, one beat every 2.7 seconds. A curve fitted to 65 records from the five blue whales of the 2026 study gives 21.9 a minute at that moment, falling to 7.7 a minute later. The first whale’s lunge peaks averaged 8.5.
Back at the surface: 33 a minute, one beat every 1.8 seconds. After a deep dive the rate was 30 to 37. The authors calculate that about 33 is the fastest one beat can be completed, using a predicted, not measured, conduction time.
Your heart, for comparison: 85 a minute, one beat every 0.7 seconds. The typical resting pulse of a child of 6 to 8 is 85; for adults, about 71.

What a dive looks like in the records

Under water: up to 16.5 minutes, down to 184 m4–8 beats a minute at the bottom (lowest 2); about 22 right after a lunge (2026), falling to about 8 a minute later.

At the surface: 1–4 minutes25–37 beats a minute; about 33 is the estimated limit of one beat.

What it means for an animal of 23 metres that holds its breath

If a heart held the bottom-phase rate of 4 to 8 beats a minute for the whole of 16.5 minutes, the longest dive of the first tagged whale, it would beat 66 to 132 times. A child’s heart beats about 1,400 times in the same time.

A slow heart makes the oxygen in the blood last longer. The authors of the 2019 paper link the long pauses between beats to the aorta: a wide, elastic arch can take up the blood from each beat and keep it moving between beats. That is a hypothesis; its support is measurements of fin whale arteries.

The 2026 study adds that the heart does not stay slow. After a lunge, a curve fitted to the blue whales’ records starts at about 22 beats a minute and eases back to about 8 a minute later, a pattern the authors compare with a sprinter’s. The first whale’s lunge peaks averaged 8.5, so the two studies differ in level. At the surface the heart works close to its ceiling, and the 2019 authors suggest that this ceiling may be one of the limits on how large a whale can grow.

A researcher leaning from a small inflatable boat holds a long pole with a tag on its end against the back of a whale that has just surfaced. — A suction-cup tag being placed on a humpback whale in Stellwagen Bank National Marine Sanctuary. Blue whales are tagged the same way, with a pole from a small boat. Photograph: NOAA National Marine Sanctuaries, public domain.National Marine Sanctuaries, Public domain, Wikimedia Commons

What is said, and what the sources show

Six claims about the heart, each set against the source it comes from.

Wrong in size, overstated in weight

A heart the size of a car

What is said. SeaWorld’s fact sheet: the heart “may weigh 908 kg … as much as a small car”. A NOAA photograph caption: “the size of a VW Beetle”.

What the sources show. The Toronto heart was weighed at 175 kg, 19 to 24 % of a Beetle’s mass, and measures 96 by 106 cm against the car’s 4.1 by 1.5 m. Whalers who weighed 32 blue whale hearts in 1947–49 found 112 to 750 kg; only the heaviest reached the mass of the lightest Beetle (730 kg), and SeaWorld’s 908 kg is above all 32.

Limit. Across the 32 weighings, taking the Toronto heart’s proportions and the same density, even the heaviest heart would scale to about 1.7 m long, under half of the Beetle’s 4.1 m.

Not supported

A child could swim through the aorta

What is said. A NOAA photograph caption: the aorta is “large enough for a human to crawl through”.

What the sources show. Press accounts of the museum’s work say it fits a human head, not a body. The reports give 20 cm and 23 cm. A two-year-old’s shoulders average 23.9 cm across; an eight-year-old’s, 31.4 cm.

Limit. Neither report shows the living width, and no source read for this page gives a measured blue whale aorta.

True at the lowest reading

A heart that beats twice a minute

What is said. The claim in the title of this page.

What the sources show. In the first paper’s record 2 a minute was the lowest reading of one whale. Rates of 4 to 8 were typical at depth and 25 to 37 at the surface, up to 37 being more than 18 times the lowest. In 2026, five more whales: about 22 a minute right after a lunge, easing to about 8.

Limit. The two ECG studies report six blue whale records: one in 2019 and five in 2026.

No source found

The heartbeat can be heard two miles away

What is said. NOAA Fisheries: “Its heartbeat can be heard 2 miles away!”

What the sources show. The 2019 paper recorded electrical signals with electrodes and reports no sound level or distance. None of the sources read for this page gives one.

Limit. A failed search does not show the claim is false.

Not supported as stated

It pumps 220 litres with every beat

What is said. Guinness World Records: about 58 US gallons (220 litres). NOAA: 60 gallons.

What the sources show. The 2019 paper predicts about 80 litres per beat for a 70-tonne whale, from equations for mammals. The 220 is 2.75 times that, and none of the sources shows how it was worked out.

Limit. The 80 litres is a prediction too.

Above every weighing found

The heart weighs 900 kilograms

What is said. SeaWorld: “908 kg … as much as a small car”.

What the sources show. Whalers who weighed 32 blue whales in 1947–49 found hearts of 112 to 750 kg, 347 kg on average. The Toronto heart, 175 kg, lies inside that range. SeaWorld’s figure is 1.2 times the heaviest of the 32.

Limit. Those whales were weighed piece by piece and the blood that flowed away was not counted; North Atlantic whales may differ.

What is still not known

On six points the sources give little or nothing.

One preserved heart. The Toronto specimen came from a decomposing whale and spent a year in a freezer; the paper does not say at which stage it was weighed. Whalers’ weighings of 32 other blue whales exist, from a different ocean and a different time. The Toronto whale was never weighed.
A handful of whales. The two ECG studies report six blue whale records: one in the 2019 paper and five in the 2026 study. The 2 beats a minute is in the first. In the 2026 study, 9 of 20 tagging attempts on two species gave a usable record. A 2022 paper also estimated a blue whale’s heart rate from a motion sensor rather than an electrode; it is not counted here.
The aorta. No source read for this page gives a measured diameter for a blue whale’s aorta, or for this heart’s. The two figures are from a 1959 report of a large whale of unstated species and a 2001 teaching sheet.
The sound. No sound recording of a blue whale’s heartbeat was found. The page makes its sound from the rates.
The child’s heart. The 130 g figure is calculated from a published formula, not weighed, and has a wide margin.
The car. Sizes and masses come from the makers’ figures as given on Wikipedia; the Beetle here is the original Type 1, built in many versions, so its mass is a range.

Sources and credits

Every figure on the page comes from the sources below and is recomputed when the page is built. Where a source is a press article that repeats a museum employee, the page attributes the words to the employee. Quotations from the English-language sources are translated where the page is in Romanian.

The two whale papers of 2019 and 2026 are open access under a licence that forbids adaptation; they are cited, not reproduced.

Goldbogen, J. A. et al. 2019. Extreme bradycardia and tachycardia in the world’s largest animal. PNAS 116: 25329–25332. doi:10.1073/pnas.1914273116. The heart rates of the first tagged blue whale.
Blawas, A. M. et al. 2026. Sprint-like cardiac dynamics support repeated acrobatic lunges in foraging rorqual whales. PNAS 123: e2613082123. doi:10.1073/pnas.2613082123. Five more blue whales and four humpback whales, tagged 2023–2025.
Miller, J. R. et al. 2017. The challenges of plastinating a blue whale (Balaenoptera musculus) heart. Journal of Plastination 29(2). doi:10.56507/SJTL1096. Weight, dimensions and identity of the Royal Ontario Museum’s heart, by the team that preserved it.
Royal Ontario Museum, news release of 18 May 2017, Blue Whale Heart Arrives at the ROM, and the exhibition page Out of the Depths: nine blue whales died in the ice in 2014.
CBC News, 18 June 2015, Heart of blue whale beached in Rocky Harbour being dissected, preserved (Mark Engstrom on the Volkswagen), and 4 January 2016, Avoiding heartbreak.
Smithsonian Magazine, 2017, The Painstaking Process of Preserving a 400-Pound Blue Whale Heart (Jacqueline Miller of the museum on the Smart car).
The Korea Times, 14 September 2015, World’s biggest heart: 180kg of blue whale, relaying the BBC and the museum: the aorta fits a human head, not a body.
Race, G. J. et al. 1959. A large whale heart. Circulation 19: 928–932. doi:10.1161/01.CIR.19.6.928. A dissected heart of 116 kg and an aorta of 20 cm; the abstract does not name the species.
Casper, D. 2001. Ms. Blue’s Measurements, teaching sheet, Seymour Marine Discovery Center, UC Santa Cruz (archived copy): an aorta of 9 inches; the sheet says it uses fin whale figures where blue whale figures are missing.
Gosline, J. M. and Shadwick, R. E. 1996, J. Exp. Biol. 199: 985–997, and Shadwick, R. E. and Gosline, J. M. 1994, Am. J. Physiol. 267: R805–R818: arteries of the fin whale, a smaller rorqual.
SeaWorld, Animal Bytes: Blue Whale (archived 2013), NOAA Fisheries, The Big-Hearted Blue Whale (2018) and Guinness World Records, Largest heart: the popular figures.
Nishiwaki, M. 1950. On the body weight of whales. Sci. Rep. Whales Res. Inst. 4: 184–209. Thirty-two blue whales weighed piece by piece on Antarctic factory ships in 1947–49, with the weight of each heart.
Czapanskiy, M. F. et al. 2022. An accelerometer-derived ballistocardiogram method for detecting heart rate in free-ranging marine mammals. J. Exp. Biol. 225.
Human hearts: Molina, D. K. and DiMaio, V. J., 2012 (men, 331 g) and 2015 (women, 245 g), autopsy weights; Schoppen, Z. J. et al., 2020, the formula behind the child’s figure; Buechel, E. V. et al., 2009, density of heart muscle and blood per beat in children; Kawel-Boehm, N. et al., 2015, blood per beat in adults; Ostchega, Y. et al., 2011, resting pulse.
Body sizes: ANSUR II (US Army, 2012; men, women) and Snyder, R. G. et al. 1977, Anthropometry of infants, children and youths. The ratios of hand and shoulder size to height are recomputed from these files. Cars: Volkswagen Beetle and Smart Fortwo (manufacturer figures as given on Wikipedia). Elephant heart: Falkenau, A. et al. 2026.

Photographs

Two blue whales, aerial: NOAA National Marine Sanctuaries, public domain.
Pygmy blue whale skeleton: Jeffrey from Christchurch, New Zealand, CC BY-SA 2.0, Wikimedia Commons.
Sei whale heart: Tiia Monto, CC BY-SA 3.0, Wikimedia Commons.
Tagging a humpback whale: NOAA National Marine Sanctuaries, public domain.

The heartbeat sound is generated in the browser from the rates above.