How strong is a chimpanzee? Stronger than a person of the same size, but not by much. A 2017 study in PNAS found chimp muscle makes about 1.35 times the force and power of human muscle of the same size. Claims that chimps are “5 to 8 times stronger” come from old tests that later studies could not repeat.
There is a catch. Chimps are also smaller than most adults. A male chimp weighs 40 to 55 kg (90 to 120 lb), says San Diego Zoo Wildlife Alliance. So a chimp is stronger pound for pound, but a big, fit man may match a chimp on a straight pull.
How strong is a chimpanzee? What the tests found
People have tried to measure chimp strength for a century. The results swing wildly, because you cannot tell a chimp to try its hardest. The table shows the main tests, oldest first.
| Test | What was measured | Result | How much stronger than a human? |
|---|---|---|---|
| Bauman, 1923 (Bronx Zoo) | One female chimp, Suzette, pulling a rope on a gauge | 571 kg (1,260 lb), vs 151 kg (332 lb) for a college student of her weight | About 4 times, from one angry pull |
| Finch, 1943 (Yale) | Several chimps pulling ropes for food | It took an 86 kg (190 lb) man to beat a 49 kg (107 lb) chimp | Around 1.5 to 2 times per kilogram |
| Review of studies (in O’Neill et al. 2017) | Average across earlier strength and jumping tests | About 1.5 times | About 1.5 times |
| O’Neill et al., 2017 (PNAS) | Single muscle fibres, measured in the lab, plus computer models | Chimp muscle: about 1.35 times the peak force and power | About 1.35 times, muscle for muscle |
Sources: the Bauman and Finch results are as quoted in Scholz and colleagues (2006). The review average and the 1.35 figure are from the University of Arizona release on the O’Neill study. The “how much stronger” column for Bauman and Finch is our own arithmetic from those numbers.
Are chimps stronger than humans?
Yes, muscle for muscle. The best evidence is the 2017 study led by Matthew O’Neill. His team tested tiny bundles of chimp and human muscle fibres in the lab. They measured how hard each fibre could pull and how fast it could shorten. Then they used computer models to scale up to whole muscles.
The surprise was that single fibres were very similar in both species. The difference was the mix. Chimps have about twice as many fast-twitch fibres as humans, the study found. Fast-twitch fibres give quick, powerful bursts, like jumping or yanking. Human muscle has more slow-twitch fibres, which tire slowly and suit walking and running long distances.
So it is a trade. Chimps are built for power in short bursts. Humans are built for stamina. A chimp could win a tug of war against a person its size, but a person could keep walking long after the chimp stopped.
How much stronger is a chimp than a human?
About 1.35 times, for the same amount of muscle, says the O’Neill study. The same news release says earlier studies averaged about 1.5 times. That is a real edge, but it is far from the “5 to 8 times” you see online.
Where did the “5 to 8 times stronger” myth come from?
Mostly from one chimp on one day in the 1920s. Researcher John Bauman set up a pulling gauge at the Bronx Zoo in New York. A female named Suzette, once a circus performer, grabbed the rope and pulled 571 kg (1,260 lb). A college student of her weight could pull only about 151 kg (332 lb), as quoted by Scholz and colleagues.
That one angry pull was quoted for decades. But when Glen Finch tested chimps at Yale in 1943, the results were far less dramatic. It still took a 86 kg (190 lb) man to beat a 49 kg (107 lb) chimp in a rope pull, but that is nothing like five times. Later writers mixed these numbers together, and the gap grew with each retelling.
The old page here even said a chimp could bench press 567 to 907 kg (1,250 to 2,000 lb). We found no source for this. Chimps have never been tested on a bench press, and the number would beat every human world record by a wide margin.
How strong is a chimp’s grip and bite?
Nobody has measured either one properly. You may read that a chimp’s grip is 200 kg (441 lb) or 330 kg (727 lb). We found no study or zoo record behind these numbers, so treat them as guesses.
What we do know is that chimps have long canine teeth, and males use them in fights. Chimp bites can cause serious injuries, which is one reason chimps are not safe pets. For animals whose bites have been measured or modelled, see which animal has the strongest bite force.
Why are chimpanzees so strong?
Three things add up. First, muscle type: about twice as many fast-twitch fibres as us. Second, build: long, powerful arms for climbing, and a body that carries less fat than most people. Third, lifestyle: chimps climb, swing and knuckle-walk every day, says San Diego Zoo Wildlife Alliance.
The O’Neill team think the change in humans went the other way. As our ancestors walked and ran longer distances, muscles with more slow-twitch fibres were an advantage. We gave up some power for staying power.
Is a chimpanzee stronger than a gorilla?
No. A gorilla is far heavier, and more muscle means more force. A male gorilla weighs about 136 to 181 kg (300 to 400 lb), three times a male chimp. No one has measured gorilla strength, though. See how strong gorillas are and how strong orangutans are for the other great apes.
Are chimpanzees endangered?
Yes. The chimpanzee is listed as Endangered on the IUCN Red List, according to a 2016 IUCN announcement. San Diego Zoo Wildlife Alliance lists the threats as hunting for meat, the illegal pet trade, killing to protect crops, and loss of forest.
Quick facts: chimpanzee strength
- Muscle for muscle: about 1.35 times human strength (O’Neill et al. 2017).
- Fast-twitch fibres: about twice as many as humans.
- Male weight: 40 to 55 kg (90 to 120 lb); female 32 to 45 kg (70 to 100 lb).
- Grip, bite and punch: never properly measured.
- “5 to 8 times stronger”: no good evidence.
Frequently asked questions
Could a chimpanzee beat a human in a fight?
Almost certainly, and it could cause serious harm. A chimp is stronger for its size, climbs and moves fast, and has long canine teeth. Chimps that attack people usually bite the face and hands. This is why keeping chimps as pets is dangerous and illegal in many places.
Is a baby chimp stronger than a human?
A baby chimp weighs about 1.9 kg (4 lb) at birth, says San Diego Zoo Wildlife Alliance, and it clings to its mother's fur from the start. Young chimps grip well, but there is no measured test showing a baby chimp is stronger than a child of the same size.
Why can humans throw better than chimps?
Humans have shoulders, waists and wrists built for fast overarm throws, and our muscles suit steady effort. Chimps have a higher share of fast-twitch fibres for power, but their shoulders are built for climbing and hanging, so their throws are strong but not accurate.
How long do chimpanzees live?
In zoos, chimps live on average 32 years for males and 40 years for females, according to San Diego Zoo Wildlife Alliance. They stay with their mothers until about age seven, which gives them time to learn skills like using sticks to fish for termites.
Sources
- Phys.org / University of Arizona (2017). Chimpanzee 'super strength' and what it might mean in human muscle evolution (news release on O'Neill et al., PNAS, doi:10.1073/pnas.1619071114).
- PubMed Central (2006). Vertical jumping performance of bonobo (Pan paniscus) suggests superior muscle properties (Scholz, D'Août, Bobbert & Aerts, Proceedings of the Royal Society B, doi:10.1098/rspb.2006.3568).
- San Diego Zoo Wildlife Alliance. Chimpanzee.
- IUCN (2016). Four out of six great apes one step away from extinction – IUCN Red List.
Sources checked 15 September 2026.
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