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How Strong Is a Boerboel’s Bite?

You’ll find confident answers everywhere — 450 PSI, 800 PSI, “9th strongest in the world.” Almost none of it is real. Here is the honest version: what dogs actually bite with, why those numbers are invented, the science that sets bite force, and the most defensible estimate we can build from peer-reviewed data.

The honest version, up front

No one has ever measured a Boerboel’s bite force. The breed appears in none of the scientific bite-force studies — not the awake-dog study, not the anaesthetised-maximum study, not the skull-modeling study.[1, 3, 4, 5] Every “Boerboel PSI” figure online is unsourced, and they contradict each other (250, 450, 800, 850), which is exactly what you’d expect from numbers that were made up rather than measured.[13, 14]

What we can do is estimate honestly. Real dogs up to 40 kg, pushed to their muscular limit in a lab, bite with 147–926 newtons at the canine teeth (and far more — up to ~3,400 N — at the rear shearing teeth).[3] Apply the published carnivore body-size scaling to a 70–90 kg Boerboel and you land at a rough 650–950 N at the canines — about a gray wolf, far below a lion.[6] That is an extrapolation, not a measurement, and we show every step below.

One more thing, because it matters: “PSI” is the wrong unit for a bite. It measures pressure, and pressure depends on tooth-tip area no one has measured. Science reports force, in newtons. Every numbered claim below links to a source you can read yourself.

On this page

  1. The honest headline: nobody has measured it
  2. Where the viral PSI numbers come from
  3. What real dogs actually bite with
  4. Force vs. pressure — why “PSI” is the wrong unit
  5. What actually sets bite force (the formula)
  6. The Boerboel’s skull, read through that formula
  7. A like-for-like comparison table
  8. A defensible estimate, shown working
  9. One owner’s first-hand account
  10. Myths vs. facts, at a glance
  11. Where the record runs out
  12. Frequently asked questions
  13. Sources & further reading

The honest headline: nobody has measured it

Start here, because everything else follows from it: there is no measurement of a Boerboel’s bite force anywhere in the scientific literature. We went looking in the actual studies — the ones that put transducers in dogs’ mouths or built validated models — and the word “Boerboel” does not appear in any of them.[1, 3, 4, 5] The breed is simply not in the data.

That should make you suspicious of every confident number you’ve read. A “vet-reviewed” chart lists the Boerboel at 450 PSI; a content site calls it the “9th strongest bite in the world”; social posts insist on 800 or 850 PSI.[13, 14] None of them cite a study, because there isn’t one. And notice they don’t even agree with each other — the spread runs from about 250 to 850. Real measurements of the same thing cluster; invented numbers scatter. This scatter is the tell.

Why this article exists. “We don’t know” is an unsatisfying answer, so the internet filled the gap with confident fiction. We’d rather give you the real thing: what has actually been measured in dogs, the physics that governs bite force, and the most defensible estimate those facts allow — clearly labelled as an estimate, not dressed up as a measurement.

Where the viral PSI numbers come from

Trace the famous dog-bite PSI lists back far enough and you reach two places, neither of them a study. The first is a single 2005 National Geographic television programme, in which Dr. Brady Barr had three dogs bite a padded sleeve. That demonstration is the origin of the endlessly-repeated “average dog ≈ 320 PSI.” The canine scientist Stanley Coren went back to the footage: the three dogs actually averaged about 269 pounds, with a Rottweiler highest at 328 — a TV demo on three animals, not a measured breed average.[8]

The second place is each other. The per-breed lists copy one another, adding and dropping breeds and numbers as they go, until a Kangal is “743 PSI” and a Boerboel is “450 PSI” with no one able to point to where those figures were taken.[13] Even the pages that call themselves “vet-reviewed” quietly admit the breed numbers are not from a single study and are imprecise.[13] For the Boerboel specifically, the “up to 450 PSI, 9th strongest” claim sits on an affiliate content site with no citation at all.[14]

There’s a deeper problem underneath the sourcing one. The single peer-reviewed study people think these numbers come from — a 2009 paper that modeled bite force for many skull types — reports its results in newtons, not PSI; gives calculated, not measured, values; and shows the force is very different at the front teeth than the back.[4] The viral single-PSI-per-breed numbers get all three of those wrong at once.

What real dogs actually bite with

Here’s the ground truth the estimates are anchored to. There are two honest ways to measure a dog’s bite, and they give very different numbers — which is the first clue that “one bite-force number” is a fiction.

Voluntary bites (awake dogs). In the only study of its kind, 22 pet dogs (7–55 kg) bit a padded strain-gauge transducer of their own accord. The forces ranged from 13 to 1,394 N, but averaged only about 256 N, with a median of 163 N.[1] A dog biting because it wants to bites surprisingly softly — it is using motivation, not muscle.

Maximal bites (anaesthetised, stimulated). To find the true ceiling, a separate study anaesthetised 20 dogs (5–40 kg) and electrically stimulated their jaw muscles to full contraction. Those same-sized dogs now produced 147–926 N at the canine teeth and 574–3,417 N at the carnassials (the big rear shearing teeth).[3] This is force a dog essentially never produces on purpose.[2]

Front teeth vs. back teeth — not the same number

Notice the canine figures (147–926 N) are three to six times lower than the carnassial figures (574–3,417 N) in the very same dogs.[3, 2] The rear teeth sit closer to the jaw hinge, so the jaw lever has more mechanical advantage there. This is why any honest bite-force figure has to say where on the jaw — and why a single “breed = X” number is meaningless.

Force vs. pressure — why “PSI” is the wrong unit

This is the part almost every “bite force” article gets wrong. Force and pressure are not the same quantity. Force — how hard the jaw pushes — is measured in newtons (N) or pounds-force (lbf). Pressure — force concentrated over an area — is measured in PSI (pounds per square inch) or megapascals, and it equals force divided by the contact area.[8]

That division is the catch. The same jaw force gives a wildly different PSI depending on how sharp the tooth tip is and how much of it touches. Press 900 N through a needle-fine point and the PSI is enormous; press the same 900 N through a broad flat surface and the PSI is modest — same force, same dog, completely different “PSI.” Because nobody has measured a dog’s tooth-contact area, a clean “breed PSI” cannot even be calculated.[8, 2] That is precisely why serious studies report force in newtons and never publish a breed PSI table.[2]

So when you see “the Boerboel bites at 450 PSI,” two things are wrong at once: the number has no source, and the unit can’t describe a bite without an area no one measured. Throughout this page we therefore talk in newtons (and give pounds-force for intuition: 1 N ≈ 0.22 lbf).

What actually sets bite force (the formula)

You asked for a formula that ties bite force to jaw size, muscle and skull shape — and one genuinely exists. It is the engine behind every credible bite-force study, and it’s not mysterious. The jaw is a lever pivoting at the joint in front of the ear; the closing muscles pull up on it, and the teeth deliver the force at the other end:

bite force = ( muscle cross-section × muscle tension × in-lever ) ÷ out-lever

summed over the three jaw-closing muscles (temporalis, masseter, medial pterygoid)

Unpacking the terms — each is something you can almost see in a dog’s head:

  • Muscle cross-section (PCSA). The thickness of the jaw-closing muscles. Bigger muscles, more force. Their force is their cross-sectional area times a near-constant “specific tension” of about 30 N/cm² that holds across mammals.[5, 7] This is the single biggest driver — muscle size matters more than the leverage.
  • In-lever and out-lever (the leverage). The in-lever is how far the muscle pulls from the hinge; the out-lever is how far the biting tooth is from the hinge. A shorter muzzle shortens the out-lever and multiplies the force — which is why a short, broad head bites harder than a long one of the same size.[5, 2]
  • Where on the tooth row. Same dog, more force at the back teeth than the front, because the back teeth have a shorter out-lever.[3, 2]

The measurements bear this out. Across dogs, bite force rises strongly with skull and jaw size (it tracks mandible size with an R² of 0.54), and — at equal skull length — brachycephalic (short, broad) skulls out-bite long-muzzled ones.[4, 5] One honest caveat: the simple “dry skull” version of this calculation actually under-predicts real bite force (it captures only about 61% of the true value at the canines), so it has to be calibrated against live measurements — and even then, models can miss in both directions.[3, 9]

The Boerboel’s skull, read through that formula

Now point that formula at a Boerboel. The breed standard describes a head that is “blocky, broad, deep and square,” with a flat, square skull and a broad, deep muzzle running about a third of the head’s length.[11] In the language of the formula, that is a head built to bite hard: a broad, deep skull means large jaw muscles (big cross-section), and a short, square muzzle means a short out-lever (high mechanical advantage). That is the same combination that puts molossoid breeds like the Rottweiler at the top of the modeled rankings.[4, 5]

The honest snag is the other input: size. The formula needs a body mass, and the breed standards deliberately don’t give one — the AKC and UKC define the Boerboel by height (males ideally about 26 inches / 66 cm), with weight described only as “in proportion.”[11, 12] In practice, adult males are usually cited at roughly 70–90 kg (150–200 lb), and that is the working range we use below; a leaner, standard-built dog would sit a little lower. (The one Boerboel-specific genetics paper to date is a pedigree study — it records no body weights and no bite data, so it can’t help here.[15])

So the qualitative answer is clear and well-supported: a Boerboel has the build of a hard-biting dog. Turning that into a number requires extrapolation — which is the next section, with the working shown.

A like-for-like comparison table

All figures in newtons of force, not PSI. Rows tagged estimated are models or extrapolations, not direct measurements. Crucially, canine and carnassial figures are not comparable — the rear teeth always read several times higher — so they’re split into two tables.

At the canine (front fang) teeth

Animal / breedBite forceHow we know
Boerboel, adult male (this estimate)~650–950 Nest.Estimated — extrapolation; never measured
Gray wolf593 Nest.Estimated (Wroe 2005)
African wild dog428 Nest.Estimated — BFQ 142, hardest-biting living carnivoran for its size
Dingo (a domestic-dog proxy)313 Nest.Estimated (Wroe 2005)
Spotted hyena773 Nest.Estimated (Wroe 2005)
Lion1,768 Nest.Estimated (Wroe 2005)
Tiger1,525 Nest.Estimated (Wroe 2005)
Pet dogs, awake & voluntary (7–55 kg)13–1,394 N (mean 256)Measured (Lindner 1995)
Dogs ≤40 kg, maximally stimulated147–926 NMeasured in vivo (Ellis 2008)

At the carnassial (rear shearing) teeth — higher, and not comparable to the above

Animal / breedBite forceHow we know
Dogs ≤40 kg, maximally stimulated574–3,417 NMeasured in vivo (Ellis 2008)
Belgian Malinois688–1,094 NMeasured in vivo (Brassard 2020)
Rottweiler~2,172 Nest.Modeled — hardest biter of 47 breeds (Brassard 2020)
Pit bull~2,051 Nest.Modeled (Brassard 2020)
Large broad-skulled dog~3,800–3,900 Nest.Predicted from a dry skull, not measured (Ellis 2009)

Canine/BFQ comparison figures for wild species from Wroe et al. 2005, Table 1 (re-checked against the original)[6]; measured dog figures from Ellis 2008[3] and Lindner 1995[1]; modeled breed figures from Brassard 2020[5]; large-skull prediction from Ellis 2009.[4]

A defensible estimate, shown working

Since nobody has measured the breed, the most we can responsibly do is extrapolate from animals that have been measured — and show every step, so you can judge it yourself. Here is the reasoning, start to finish.

The tool. A landmark comparative study fitted a relationship between body mass and canine bite force across the carnivores — wolves, big cats, hyenas and more. The fit is tight (it explains about 85% of the variation), and bite force rises with roughly the 0.6 power of body mass.[6] We checked the tool before trusting it: re-running that relationship reproduces the paper’s own published figures for the wolf, lion, tiger and hyena almost exactly, so we know it’s faithful.

The inputs. A male Boerboel of about 70–90 kg, with a broad, short-muzzled skull. To place a domestic dog on the scale we use a “bite-force quotient” (how hard an animal bites for its size, with 100 being average) anchored to the dingo’s measured value of 108 — a fair domestic-dog stand-in — and allow a modest premium up to ~120 for the Boerboel’s harder-biting skull shape.[6]

The working, at the canines

  • Size-average dog (quotient 100): 70 kg → ~666 N; 80 kg → ~722 N; 90 kg → ~774 N.
  • Domestic-dog quotient (108, like the dingo): 70 kg → ~719 N; 90 kg → ~836 N.
  • With a broad-skull premium (up to 120): 90 kg → ~929 N.
  • Estimated range ≈ 650–950 N at the canines (about 146–214 lbf of force).

The sanity checks. Real dogs up to 40 kg, maxed out in the lab, already reached 926 N at the canines.[3] A Boerboel is roughly twice that body weight, so an estimate that lands at — not far above — that measured ceiling is conservative, not inflated. Independently, the dry-skull models (once corrected for the under-prediction we flagged earlier) put a big dog’s canine force in a band that comfortably contains our range.[3, 4] Three different methods point to the same neighbourhood.

Read this estimate honestly. It is an order-of-magnitude figure, not a measurement. The relationship we used was fitted to wild carnivores, so applying it to a domestic mastiff is an assumption; the quotient band is a judgement call; and the whole thing rests on a body weight the breed standard never actually fixes. The right way to say it: “no one has measured a Boerboel’s bite, but its size and skull put a reasonable estimate around 650–950 newtons at the canines — roughly a gray wolf, well below a big cat.” And no, that still doesn’t convert to a clean PSI — over a realistic range of tooth-contact areas the same force spans anywhere from about 4,700 to 13,500 PSI, which tells you how meaningless a single PSI figure really is.[8, 2]

One owner’s first-hand account

Numbers aside, we can offer something the studies can’t: a first-hand sense of what that force feels like. We’ll be clear that this is an anecdote, not data — but it’s an honest one, and it lines up with the physics in an interesting way.

“I was accidentally caught by a Boerboel that was in a fight. That one bite didn’t tear or sting — there was no slicing feeling at all. What I felt was pressure: a deep, crushing high-pressure squeeze, more like being caught in a machine press than what you’d picture as a dog bite. It wasn’t measured in any way. It’s just what it felt like.”

Here’s why that description is worth more than it might seem. The science says a Boerboel is built for force — big jaw muscles and short-muzzle leverage producing crushing power — rather than for the fine, shearing, skin-tearing bite of a lighter, narrower-jawed dog. A broad, blunt molossoid bite delivers that high force over a relatively wide contact, so it registers as a press, not a slash. The “machine press, no tearing” sensation is exactly what you’d predict from the morphology.[5, 4]

We include this for two reasons. First, because it’s true, and a source-of-truth page shouldn’t hide useful first-hand experience just because it isn’t a lab reading. Second, because it makes the practical point better than any number: a Boerboel’s bite is not something to test or take lightly. The figures on this page exist to satisfy curiosity — not to encourage anyone to find out the hard way.

Myths vs. facts, at a glance

The claim

A Boerboel bites at 450 / 800 / 850 PSI.

What the record shows

No Boerboel bite has ever been measured, and these numbers cite no study. They also disagree with each other — the hallmark of invented figures.

The claim

PSI is how you measure a bite.

What the record shows

PSI is pressure (force ÷ contact area). Bites are reported as force, in newtons. A PSI figure can't even be calculated without a tooth-contact area no one has measured.

The claim

There's one bite-force number for the breed.

What the record shows

Even for one dog there isn't. The rear (carnassial) teeth read 3–6× higher than the canines, and a maxed-out lab bite is far above a voluntary one.

The claim

The famous '320 PSI average dog' comes from a study.

What the record shows

It comes from a 2005 TV demonstration on three dogs. Re-examined, they averaged about 269 pounds — a demo number, not a measured average.

The claim

The Boerboel has the strongest bite of any dog.

What the record shows

It's likely among the stronger breeds, given its size and skull — but that's an inference, not a measured fact, and the league-table numbers online aren't from data.

The claim

Science has ranked the Boerboel against other breeds.

What the record shows

It hasn't — the breed appears in none of the bite-force studies. Modeled rankings exist for other breeds (Rottweiler, pit bull), but not this one.

Where the record runs out

A source-of-truth page should be honest about its own limits. These are the things that genuinely cannot be settled from the evidence today — anyone who states them with certainty is filling a gap with a guess.

  • The Boerboel’s actual bite force — it has never been measured or even modeled in any study.[1, 3, 4, 5]
  • Any Boerboel PSI figure — both because it’s unmeasured and because PSI needs a tooth-contact area no one has recorded.[8, 2]
  • Exactly where the breed ranks against other dogs — no measured comparison includes it.[5, 13]
  • The precise body weight to plug into the estimate — the breed standards specify height, not weight.[11, 12]
  • Whether the cross-carnivore scaling we used truly applies to a domestic mastiff — a reasonable assumption, but an assumption.[6]

Frequently asked questions

What is a Boerboel's bite force in PSI?

There is no real answer, because no one has ever measured a Boerboel's bite. The numbers you see online — 450 PSI, 800 PSI, 850 PSI — have no scientific source and disagree wildly with each other, which is the signature of a made-up figure. On top of that, PSI is the wrong unit: it measures pressure, not force, and depends on tooth-tip contact area that nobody has measured. Real bite-force science reports newtons of force, not PSI.

So how hard does a Boerboel actually bite?

Honestly: unknown, because it has never been tested. The best we can do is estimate. Applying the published body-mass-to-bite-force scaling for carnivores to a 70–90 kg male Boerboel gives a rough estimate of about 650–950 newtons of force (roughly 146–214 pounds-force) at the canine teeth — comparable to a gray wolf and far below a lion or tiger. This is an extrapolation, not a measurement, and we show the working on the page.

Is the Boerboel's bite one of the strongest of any dog?

Probably among the stronger breeds, but this cannot be stated as a measured fact. The Boerboel has never been measured, so it does not appear in any ranking that is based on real data. What the science does show is that large, broad, deep-skulled, short-muzzled (molossoid) dogs bite harder than long-nosed dogs of the same size — and the Boerboel has exactly that build — so it is reasonable to place it among the harder-biting breeds. The specific league-table numbers online are not from measurements.

Why can't you just give one number?

Three reasons. First, the breed has never been measured. Second, bite force is not a single number even for one dog — it is several times higher at the rear shearing teeth (carnassials) than at the canine tips, so any single figure is meaningless without saying where on the jaw. Third, a dog biting voluntarily uses only a fraction of its maximum; lab maxima come from electrically stimulating the jaw under anaesthesia, which a pet never does.

How is bite force actually measured, and what do real dogs score?

Two main ways. Awake dogs biting a padded transducer voluntarily: 22 pet dogs (7–55 kg) averaged about 256 N, ranging 13–1,394 N. Or anaesthetised dogs whose jaw muscles are electrically stimulated to maximum: 20 dogs (5–40 kg) produced 147–926 N at the canines and 574–3,417 N at the carnassials. The voluntary numbers are far lower because they reflect motivation, not muscle limit.

What determines how hard a dog bites?

Bite force comes down to the size of the jaw-closing muscles (their cross-sectional area), how the jaw works as a lever (a shorter muzzle gives more mechanical advantage), and where on the tooth row you measure. In short: big jaw muscles plus a broad, deep, short skull equal a hard bite. Brachycephalic (short, broad) skulls out-bite long-muzzled skulls of the same size — and the Boerboel's square, blocky head is built that way.

Does a Boerboel bite harder than a Pit Bull, Rottweiler, or German Shepherd?

No measured comparison exists for the Boerboel, so any direct claim is guesswork. For context, a 3D-modeling study estimated the Rottweiler (~2,172 N) and pit bull (~2,051 N) as the hardest biters at the carnassials among 47 breeds. A Boerboel is heavier with a comparably broad skull, so a similar or higher figure is plausible — but it is an inference, not data.

Could a Boerboel's bite injure someone seriously?

Yes — any large guardian breed can. That is exactly why temperament, training, socialization and responsible ownership matter far more than a bite-force number. A well-raised, stable Boerboel is a discerning protector, not an indiscriminate biter. The honest takeaway of this page is not “how many PSI” but “treat the breed's strength with respect and raise it properly.”

Sources & further reading

This article leans on primary and authoritative sources — peer-reviewed bite-force studies, comparative-anatomy research and breed-standard documents — and cites the viral PSI pages only as examples of the claims it corrects, never as evidence. The key comparative table (Wroe et al. 2005) was re-verified directly against the original. Numbers in the text link here.

  1. Measurement of bite force in dogs: a pilot study (Lindner, Marretta, Pijanowski, Johnson & Smith, 1995) — the only voluntary, awake-dog bite dataset — Journal of Veterinary Dentistry / PubMed (PMID 9693626). https://pubmed.ncbi.nlm.nih.gov/9693626/
  2. Bite Forces and Their Measurement in Dogs and Cats (Kim, Arzi, et al., 2018) — authoritative review; reports force in newtons, never PSI — Frontiers in Veterinary Science 5:76. https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2018.00076/full
  3. Calibration of estimated biting forces in domestic canids: post-mortem vs in vivo (Ellis, Thomason, Kebreab & France, 2008) — in-vivo measured maxima — Journal of Anatomy / PubMed Central (PMC2423399). https://pmc.ncbi.nlm.nih.gov/articles/PMC2423399/
  4. Cranial dimensions and forces of biting in the domestic dog (Ellis, Thomason, Kebreab, Zubair & France, 2009) — 127 skulls; predicted, not measured — Journal of Anatomy 214(3):362–373 / PMC2673787. https://pmc.ncbi.nlm.nih.gov/articles/PMC2673787/
  5. Bite force and its relationship to jaw shape in domestic dogs (Brassard et al., 2020) — 47-dog 3D model validated against in-vivo Malinois — Journal of Experimental Biology 223:jeb224352. https://journals.biologists.com/jeb/article/223/16/jeb224352/223640/Bite-force-and-its-relationship-to-jaw-shape-in
  6. Bite club: comparative bite force in big biting mammals (Wroe, McHenry & Thomason, 2005) — the BFQ method and the cross-species table — Proceedings of the Royal Society B 272:619–625 / PMC1564077. https://pmc.ncbi.nlm.nih.gov/articles/PMC1564077/
  7. Cranial strength in relation to estimated biting forces in some mammals (Thomason, 1991) — the dry-skull lever method — Canadian Journal of Zoology 69:2326–2333. https://cdnsciencepub.com/doi/10.1139/z91-329
  8. Dog Bite Force: Myths, Misinterpretations and Realities (Stanley Coren, 2010) — Psychology Today. https://www.psychologytoday.com/us/blog/canine-corner/201005/dog-bite-force-myths-misinterpretations-and-realities
  9. Measurement of voluntary bite forces in large carnivores (2023) — method caveats; models err in both directions — Journal of Experimental Biology 226:jeb245255. https://journals.biologists.com/jeb/article/226/7/jeb245255/306239/Measurement-of-voluntary-bite-forces-in-large
  10. Bite forces, canine strength and skull allometry in carnivores (Christiansen & Adolfssen, 2005) — Journal of Zoology 266:133–151 (Cambridge). https://www.cambridge.org/core/journals/journal-of-zoology/article/abs/bite-forces-canine-strength-and-skull-allometry-in-carnivores-mammalia-carnivora/76A3A8B452234DC6082CBE8341713102
  11. Official Standard of the Boerboel (height and head/skull description; no weight specified) — American Kennel Club. https://images.akc.org/pdf/breeds/standards/Boerboel.pdf
  12. Breed Standards: South African Boerboel (height; size defined by height, not weight) — United Kennel Club. https://www.ukcdogs.com/south-african-boerboel
  13. Dog Bite Force: Veterinarian-Reviewed Chart of 68 Breeds — the canonical viral PSI list (cited as the claim being corrected, not as evidence) — notabully.org. https://notabully.org/dog-bite-force-chart-list/
  14. How Strong Is The Boerboel Bite Force PSI — “up to 450 PSI / 9th strongest” (cited as an example of the unsourced claim) — pawscessories.com (content aggregator). https://pawscessories.com/boerboel-bite-force/
  15. Pedigree-Based Genetic Diversity in the South African Boerboel Dog Breed (Mabunda et al., 2024) — a pedigree study; contains no body-size or bite data — Animals 14(6):975 / MDPI. https://doi.org/10.3390/ani14060975

Last reviewed June 2026. The Boerboel-specific bite-force range on this page is an explicitly-labelled estimate by extrapolation, not a measurement. Spot a genuine error or have a primary source we missed? Tell us via our contact page — we’d rather be corrected than wrong.

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