Short answer: Smithsonian reports that adult male western lowland gorillas can stand up to about 6 feet (1.8 metres), while adult females can stand up to about 4.5 feet (1.4 metres). These are upright measurements, not the posture gorillas normally use for travel.
Gorilla height and arm span
| Western lowland gorilla | Standing height | Arm span |
|---|---|---|
| Adult male | Up to about 6 ft / 1.8 m | About 8 ft / 2.4 m |
| Adult female | Up to about 4.5 ft / 1.4 m | About 6.5 ft / 2 m |
These Smithsonian figures describe western lowland gorillas. They should not be treated as exact averages for every species and individual.
Why measuring gorilla height is difficult
Gorillas usually move on all fours using knuckle-walking. Their knees, hips and spine are not normally arranged like a human posing against a height chart. Reported “standing height” varies with posture, measurement method and whether the value is observed, estimated or taken from an anesthetized individual.
Males and females differ in size
Adult males are substantially larger and heavier than adult females. Mature males also develop more prominent cranial crests and massive shoulder and upper-body musculature. The difference is an example of sexual dimorphism.
Do mountain gorillas stand taller?
Eastern gorillas are often described as more robust than western lowland gorillas, but credible comparative measurements require taxon-specific samples and consistent methods. It is safer to report sourced ranges than to declare one universal height for all mountain or silverback gorillas.
Why gorilla arms are so long
Gorillas have arms longer than their legs. Long upper limbs contribute to climbing, reaching, feeding and quadrupedal movement. Arm span can therefore appear more dramatic than upright height.
Can gorillas stand and walk upright?
Yes, gorillas can stand and take short bipedal steps, for example while displaying, carrying something or moving through particular terrain. They are not habitual human-style bipeds and normally travel by knuckle-walking.
Avoid misleading comparisons
Forced-perspective photographs, estimates based on enclosure objects and unsourced record lists are not reliable measurements. Always identify the species, sex, posture and source when comparing a gorilla with a person.
Source
Related: gorilla weight and silverback weight.