Short answer: Gorilla weight varies substantially by sex, species, age and individual. Smithsonian reports adult male western lowland gorillas average about 300 pounds (136 kilograms) and may reach about 500 pounds (227 kilograms); adult females are commonly about 150–200 pounds (68–91 kilograms).
Credible western lowland gorilla figures
| Sex | Reported weight | Source context |
|---|---|---|
| Adult male | Average about 300 lb / 136 kg; up to about 500 lb / 227 kg | Smithsonian species profile |
| Adult female | About 150–200 lb / 68–91 kg | Smithsonian species profile |
| Newborn | Average about 4 lb / 2 kg | Smithsonian reproduction data |
Why there is no single “gorilla weight”
- There are two species and four recognized subspecies.
- Adult males are much larger than adult females.
- Juveniles, adolescents and mature adults differ greatly.
- Wild and zoo-housed populations may differ in condition and measurement access.
- Studies may report averages, ranges, maxima or estimates.
Which gorillas are largest?
Eastern gorillas are generally described as more robust, while western lowland gorillas are the smallest recognized subspecies on average. However, individuals overlap, and comparative claims should rely on standardized taxon-specific datasets rather than isolated records.
What does a silverback weigh?
A silverback is a mature adult male. It is not a separate species, so its likely weight depends on whether it is a western lowland, Cross River, Grauer’s or mountain gorilla. See our focused silverback weight guide.
Are record weights useful?
Historic record claims often involve hunted specimens, captive individuals with unusual body condition, uncertain species identification or estimates rather than standardized measurements. They may document an exceptional individual but should not define what a healthy wild gorilla normally weighs.
How is weight measured?
Zoo gorillas can voluntarily step onto scales through positive-reinforcement husbandry training. Wild gorillas are not routinely handled or weighed; researchers use visual observations, photogrammetry, known growth histories and other non-invasive methods. Different methods create different uncertainty.
Weight is not a strength test
Body mass contributes to physical capacity, but it cannot be converted directly into a bench-press number or a fixed “times stronger” multiplier. Read what evidence says about gorilla strength.
Source
Editorial note: We report sourced reference values and label averages, ranges and upper figures separately.