Animal Weights: How Much Animals Weigh
Animal weights span more than eleven orders of magnitude, from insects weighing a few milligrams to the blue whale at well over 100 tonnes. The figures here are typical adult ranges. In many species males and females differ substantially, and the note on each animal page explains which sex is heavier.
214 animals, A–Z. Tap a column heading to sort.
| Animal | Class | Weight | Notes |
|---|---|---|---|
| African Buffalo | Mammals | 300–900 kg (660–1,980 lb) | adults; Cape buffalo 500–900 kg, the small forest buffalo around 300 kg |
| African Elephant | Mammals | 2,700–6,000 kg (6,000–13,200 lb) | adult females about 2,700–3,500 kg, adult males 4,500–6,000 kg |
| African Grey Parrot | Birds | 400–490 g (14–17 oz) | adults |
| African Spurred Tortoise | Reptiles | 35–90 kg (77–200 lb) | adults; females are usually under 50 kg, and the largest males pass 100 kg |
| African Wild Dog | Mammals | 18–36 kg (40–79 lb) | adults; southern African dogs are larger than East African ones |
| Alpaca | Mammals | 48–84 kg (106–185 lb) | adults; males are slightly heavier |
| American Alligator | Reptiles | 90–450 kg (200–1,000 lb) | adult females average about 90 kg; large males reach 230–450 kg |
| American Bison | Mammals | 360–900 kg (790–2,000 lb) | adults; cows 360–500 kg, bulls 700–900 kg or more |
| American Black Bear | Mammals | 40–250 kg (90–550 lb) | adults; females 40–110 kg, males 60–250 kg; heaviest in fall |
| American Bullfrog | Amphibians | 300–500 g (0.7–1.1 lb) | adults; very large individuals reach about 800 g |
| American Crow | Birds | 316–620 g (11–22 oz) | adults; males are slightly larger |
| American Lobster | Invertebrates | 0.5–4 kg (1–9 lb) | typical adults; the record is 20.1 kg (44 lb) |
| American Robin | Birds | 59–94 g (2.1–3.3 oz) | adults; average about 77 g |
| American Toad | Amphibians | about 20–60 g (0.7–2 oz) | approximate adult weight; females are larger than males |
| Andean Condor | Birds | 8–15 kg (18–33 lb) | adults; males 11–15 kg, females 8–11 kg |
| Arctic Fox | Mammals | 2.5–8 kg (5.5–17.5 lb) | adults; males average about 3.5 kg, females about 2.9 kg; heaviest in fall |
| Asian Elephant | Mammals | 2,000–5,000 kg (4,400–11,000 lb) | adult females average about 2,700 kg, adult males about 4,000 kg |
| Asian Giant Hornet | Invertebrates | roughly 2–4 g (0.07–0.14 oz) | approximate; published weights are scarce and queens are the heaviest caste |
| Atlantic Bluefin Tuna | Fish | 225–400 kg (500–880 lb) | mature adults average 225–250 kg; giants above 600 kg are records |
| Atlantic Puffin | Birds | 310–550 g (11–19 oz) | adults; northern populations are heavier |
| Atlantic Salmon | Fish | 3.5–9 kg (8–20 lb) | returning adults; grilse are lighter and rare multi-sea-winter fish exceed 20 kg |
| Axolotl | Amphibians | 60–225 g (2–8 oz) | adults |
| Bactrian Camel | Mammals | 300–1,000 kg (660–2,200 lb) | adults; males are much heavier than females |
| Bald Eagle | Birds | 3–6.3 kg (6.6–14 lb) | adults; females are about 25% heavier than males, and Alaskan birds are the largest |
| Ball Python | Reptiles | 1–2.5 kg (2.2–5.5 lb) | adults; females are larger than males |
| Barn Owl | Birds | 300–700 g (0.7–1.5 lb) | adults; females are heavier, and American birds are larger than European ones |
| Beluga Sturgeon | Fish | 19–264 kg (42–582 lb) | mature fish caught in recent decades; historic giants exceeded 1,000 kg |
| Beluga Whale | Mammals | 700–1,600 kg (1,540–3,530 lb) | adults; females 700–1,200 kg, males 1,100–1,600 kg |
| Betta Fish | Fish | about 2–5 g (0.07–0.18 oz) | approximate adult weight; bettas are rarely weighed |
| Black Garden Ant | Invertebrates | about 1–2 mg (0.00004–0.00007 oz) | workers, approximate; queens are many times heavier |
| Black Mamba | Reptiles | about 1–1.6 kg (2.2–3.5 lb) | typical adults |
| Black Rhinoceros | Mammals | 800–1,400 kg (1,760–3,090 lb) | adults; males and females are similar in size |
| Blue Whale | Mammals | 100–150 tonnes (110–165 US tons) | adults; the heaviest recorded, Antarctic females, approached 190 tonnes |
| Blue Wildebeest | Mammals | 120–270 kg (265–595 lb) | adults; bulls are heavier than cows and can reach about 290 kg |
| Boa Constrictor | Reptiles | 10–27 kg (22–60 lb) | adults; females are larger, and exceptional females exceed 40 kg |
| Bobcat | Mammals | 4–18 kg (9–40 lb) | females 4–15 kg, males 6.4–18 kg; largest in the north of the range |
| Bonobo | Mammals | 30–60 kg (66–132 lb) | adults; females average about 33 kg, males about 45 kg |
| Bornean Orangutan | Mammals | 30–100 kg (66–220 lb) | adults; females 30–50 kg, flanged males 50–100 kg |
| Bottlenose Dolphin | Mammals | 150–650 kg (330–1,430 lb) | adults; size varies greatly between populations, with cold-water dolphins the largest |
| Bowhead Whale | Mammals | 75–100 tonnes (83–110 US tons) | adults; females are larger than males |
| Brown Rat | Mammals | 200–500 g (7–18 oz) | adults; males are larger than females |
| Brown-Throated Sloth | Mammals | 2.25–6.3 kg (5–14 lb) | adults; females are slightly larger |
| Budgerigar | Birds | 30–40 g (1.1–1.4 oz) | wild-type and ordinary pet birds; large English show budgies weigh 45–65 g |
| Buff-Tailed Bumblebee | Invertebrates | 0.1–0.9 g (0.004–0.03 oz) | approximate; workers about 0.1–0.35 g, queens about 0.6–0.9 g |
| Bull Shark | Fish | 90–230 kg (200–500 lb) | adults; females average about 130 kg and males about 95 kg |
| Burmese Python | Reptiles | 30–90 kg (66–200 lb) | large adults; females are heavier, and obese captives have exceeded 180 kg |
| California Sea Lion | Mammals | 100–350 kg (220–770 lb) | adult females about 100 kg, adult males about 300–350 kg |
| Canada Goose | Birds | 2.4–6.5 kg (5.3–14.3 lb) | adults; varies widely by subspecies, and males are larger |
| Cane Toad | Amphibians | 0.2–1.3 kg (0.4–2.9 lb) | adults; females are heavier, and most toads weigh well under 1 kg |
| Capybara | Mammals | 35–66 kg (77–146 lb) | adults; females are slightly heavier than males |
| Cat | Mammals | 3.5–5 kg (8–11 lb) | typical adults; large breeds such as the Maine Coon can exceed 8 kg |
| Central Bearded Dragon | Reptiles | 300–500 g (11–18 oz) | healthy adults |
| Cheetah | Mammals | 21–65 kg (46–143 lb) | adults; males are slightly heavier than females |
| Chicken | Birds | 1.5–4 kg (3.3–8.8 lb) | adult standard breeds; bantams are under 1 kg and the largest breeds exceed 5 kg |
| Chimpanzee | Mammals | 27–70 kg (60–155 lb) | adults; females 27–50 kg, males 40–70 kg |
| Chinese Giant Salamander | Amphibians | 25–30 kg (55–66 lb) | average large adults; records reach about 50 kg, and most wild animals today are much smaller |
| Cockatiel | Birds | 80–100 g (2.8–3.5 oz) | adults |
| Common Earthworm | Invertebrates | 3–10 g (0.1–0.35 oz) | adults |
| Common Octopus | Invertebrates | 3–10 kg (6.6–22 lb) | adults; most weigh about 3 kg, large individuals reach about 10 kg |
| Common Ostrich | Birds | 90–145 kg (200–320 lb) | adults; females about 90–110 kg, males about 100–145 kg, with exceptional males over 150 kg |
| Common Raven | Birds | 0.7–1.6 kg (1.5–3.5 lb) | adults; size varies by region, with the largest birds in the far north and the Himalayas |
| Common Starfish | Invertebrates | roughly 50–400 g (2–14 oz) | approximate wet weight of adults 10–30 cm across; varies greatly with size and feeding |
| Common Swift | Birds | 36–52 g (1.3–1.8 oz) | adults |
| Common Vampire Bat | Mammals | 25–40 g (0.9–1.4 oz) | adults before feeding; a full meal can add half as much again |
| Common Warthog | Mammals | 45–150 kg (100–330 lb) | adults; sows 45–75 kg, boars 60–150 kg |
| Common Wasp | Invertebrates | roughly 70–250 mg (0.002–0.009 oz) | approximate; workers are under about 100 mg, queens considerably heavier |
| Common Wombat | Mammals | 20–35 kg (44–77 lb) | adults; Tasmanian and island animals are smaller |
| Cougar | Mammals | 29–100 kg (64–220 lb) | females 29–64 kg, males 53–100 kg; largest far from the equator |
| Cow | Mammals | 400–1,100 kg (880–2,400 lb) | adult cows 400–800 kg, bulls of large breeds 900–1,100 kg or more |
| Coyote | Mammals | 7–21 kg (15–46 lb) | adults; males slightly heavier, and northeastern coyotes are the largest |
| Dog | Mammals | 1.5–90 kg (3–200 lb) | depends on breed, from Chihuahuas to English Mastiffs |
| Donkey | Mammals | 80–480 kg (180–1,060 lb) | from miniature donkeys to mammoth breeds; a standard donkey weighs about 160–250 kg |
| Dromedary Camel | Mammals | 300–600 kg (660–1,320 lb) | females 300–540 kg, males 400–600 kg |
| Eastern Gray Squirrel | Mammals | 400–600 g (14–21 oz) | adults; heavier in the north and in fall |
| Eastern Newt | Amphibians | about 2–4 g (0.07–0.14 oz) | approximate adult weight |
| Electric Eel | Fish | up to about 20 kg (44 lb) | large adults; most are lighter |
| Elk | Mammals | 225–330 kg (500–730 lb) | typical adults; cows average about 225 kg, bulls about 320 kg; Roosevelt elk bulls can exceed 450 kg |
| Emperor Dragonfly | Invertebrates | about 1 g (0.035 oz) | adults; approximate |
| Emperor Penguin | Birds | 22–45 kg (49–99 lb) | adults; weight swings widely over the year as birds fatten up and then fast |
| Emperor Scorpion | Invertebrates | about 30 g (1.1 oz) | typical adult; pregnant females can be heavier |
| Emu | Birds | 30–55 kg (66–121 lb) | adults; females average slightly heavier than males |
| European Hare | Mammals | 3–5 kg (6.6–11 lb) | adults; females are slightly heavier |
| European Hedgehog | Mammals | 600–1,200 g (1.3–2.6 lb) | adults; heaviest in fall before hibernation |
| European Mantis | Invertebrates | roughly 1–4 g (0.04–0.14 oz) | adults, approximate; egg-laden females are heaviest and males much lighter |
| Fennec Fox | Mammals | 0.8–1.9 kg (1.8–4.2 lb) | adults; the smallest of all wild canids |
| Fire Salamander | Amphibians | about 20–40 g (0.7–1.4 oz) | approximate adult weight; a typical adult is around 40 g |
| Galápagos Tortoise | Reptiles | 110–270 kg (250–600 lb) | adults of the large domed forms; females are much lighter than males, and record males exceed 400 kg |
| Garden Snail | Invertebrates | 7–15 g (0.25–0.5 oz) | adults, including the shell |
| Giant Anteater | Mammals | 27–50 kg (60–110 lb) | adults; males 33–50 kg, females 27–47 kg |
| Giant Clam | Invertebrates | 100–250 kg (220–550 lb) | large adults; the shell makes up most of the weight |
| Giant Manta Ray | Fish | about 1,200–2,000 kg (2,650–4,400 lb) | large adults; the heaviest recorded are around 2,400–3,000 kg |
| Giant Panda | Mammals | 70–125 kg (155–275 lb) | adults; males are 10–20% heavier and large males can reach about 160 kg |
| Giant Squid | Invertebrates | 150–275 kg (330–610 lb) | large adults; males reach about 150 kg, females about 275 kg |
| Gila Monster | Reptiles | 350–700 g (12–25 oz) | typical adults; large, well-fed individuals can reach about 2 kg |
| Giraffe | Mammals | 800–1,200 kg (1,760–2,650 lb) | adult averages: females about 830 kg, males about 1,190 kg; the largest bulls approach 1,900 kg |
| Goat | Mammals | 20–140 kg (44–310 lb) | depends on breed, from pygmy goats to large Boer and Saanen bucks |
| Golden Eagle | Birds | 3–6.5 kg (6.6–14.3 lb) | adults; males about 3–4.5 kg, females about 4–6.5 kg |
| Golden Poison Frog | Amphibians | up to about 30 g (1 oz) | approximate adult weight; the largest of the poison dart frogs |
| Goldfish | Fish | 100–500 g (3.5 oz–1.1 lb) | adult common goldfish; pond fish are heaviest and rare giants exceed 2 kg |
| Goliath Birdeater | Invertebrates | up to about 175 g (6.2 oz) | large adults; about 175 g is the maximum reported |
| Goliath Frog | Amphibians | 0.6–3.3 kg (1.3–7.2 lb) | adults; the largest individuals weigh just over 3 kg |
| Gray Wolf | Mammals | 23–65 kg (50–145 lb) | adults; size increases toward the north, where large males can reach 80 kg |
| Great Hammerhead Shark | Fish | 230–450 kg (500–1,000 lb) | adults; the record is a 580 kg pregnant female |
| Great Horned Owl | Birds | 0.9–2.5 kg (2–5.5 lb) | adults; males average about 1.2 kg and females about 1.6 kg |
| Great White Shark | Fish | 520–1,100 kg (1,150–2,400 lb) | adults; females are larger, and the biggest females are estimated at close to 2,000 kg |
| Greater Flamingo | Birds | 2–4 kg (4.4–8.8 lb) | adults; males are larger than females |
| Green Anaconda | Reptiles | 30–80 kg (65–175 lb) | adults; females are far heavier than males, and the largest females exceed 100 kg |
| Green Iguana | Reptiles | 4–8 kg (9–18 lb) | adults; large males are heaviest |
| Green Sea Turtle | Reptiles | 110–190 kg (240–420 lb) | nesting adults; exceptional animals exceed 300 kg |
| Greenland Shark | Fish | about 300–1,000 kg (660–2,200 lb) | adults; most weigh a few hundred kilograms and the largest about 1,000 kg or more |
| Grizzly Bear | Mammals | 130–360 kg (290–790 lb) | inland adults; females 130–180 kg, males 180–360 kg; coastal brown bears are heavier |
| Guinea Pig | Mammals | 700–1,200 g (1.5–2.6 lb) | adults; males (boars) are heavier than females (sows) |
| Guppy | Fish | about 0.1–1 g (under 0.04 oz) | approximate; small males at the low end, large females at the top |
| Hamster | Mammals | 100–150 g (3.5–5.3 oz) | adults; females are larger than males and well-fed pets can be heavier |
| Harbor Seal | Mammals | 55–170 kg (120–375 lb) | adults; males are somewhat larger than females |
| Hippopotamus | Mammals | 1,300–3,200 kg (2,870–7,050 lb) | adults; females average about 1,300–1,500 kg, males 1,500–3,200 kg |
| Honey Badger | Mammals | 5–16 kg (11–35 lb) | adults; males 9–16 kg, females 5–10 kg |
| Horse | Mammals | 380–1,000 kg (840–2,200 lb) | light riding horses 380–550 kg, heavy draft breeds 700–1,000 kg |
| House Mouse | Mammals | 12–30 g (0.4–1.1 oz) | adults; pet and lab mice are often heavier |
| Housefly | Invertebrates | about 10–20 mg (0.0004–0.0007 oz) | adults; females are larger than males |
| Humpback Whale | Mammals | 25–40 tonnes (28–44 US tons) | adults; females are slightly larger than males |
| Immortal Jellyfish | Invertebrates | — | |
| Indian Cobra | Reptiles | about 1–2.5 kg (2.2–5.5 lb) | approximate adult range; few published weights exist |
| Indian Peafowl | Birds | 2.75–6 kg (6–13 lb) | adults; peacocks 4–6 kg, peahens 2.75–4 kg |
| Indo-Pacific Sailfish | Fish | 30–100 kg (65–220 lb) | adults; the angling record is 100 kg |
| Jaguar | Mammals | 56–96 kg (123–212 lb) | typical adults; Pantanal males can exceed 130 kg, Central American females may weigh under 45 kg |
| Japanese Macaque | Mammals | 8–11 kg (18–24 lb) | adult averages: females about 8.4 kg, males about 11.3 kg; northern animals are heavier |
| Japanese Spider Crab | Invertebrates | 16–19 kg (35–42 lb) | large adult males; females are considerably smaller |
| King Cobra | Reptiles | 5–9 kg (11–20 lb) | typical adults; the heaviest recorded captive weighed 12.7 kg |
| Koala | Mammals | 4–15 kg (9–33 lb) | adults; southern koalas and males are heaviest |
| Koi | Fish | 4–12 kg (9–26 lb) | adult pond koi; jumbo strains can be heavier |
| Komodo Dragon | Reptiles | 70–90 kg (154–200 lb) | adults; males are heavier than females, and gorged animals weigh far more |
| Largemouth Bass | Fish | 0.5–4.5 kg (1–10 lb) | adults; the world record is 10.1 kg |
| Leatherback Sea Turtle | Reptiles | 250–700 kg (550–1,540 lb) | adults; the record is a 916 kg male |
| Leopard | Mammals | 20–72 kg (44–159 lb) | females 20–43 kg, males 30–72 kg; size varies widely by region |
| Leopard Gecko | Reptiles | 45–80 g (1.6–2.8 oz) | adults; males are heavier than females |
| Lined Seahorse | Fish | about 5–20 g (0.2–0.7 oz) | approximate adult weight; seahorses are rarely weighed |
| Lion | Mammals | 120–190 kg (265–420 lb) | adults; females 120–150 kg, males 150–190 kg |
| Llama | Mammals | 130–200 kg (290–440 lb) | typical adults; exceptionally large animals are reported at up to about 270 kg |
| Luna Moth | Invertebrates | roughly 1–2 g (0.04–0.07 oz) | adults; approximate, since adult weight is rarely measured and females full of eggs are heaviest |
| Mallard | Birds | 0.7–1.6 kg (1.5–3.5 lb) | adults; drakes are slightly heavier than hens |
| Mandrill | Mammals | 10–37 kg (22–82 lb) | adults; females 10–15 kg, males 19–37 kg |
| Meerkat | Mammals | 620–970 g (1.4–2.1 lb) | adults; dominant females are often heaviest |
| Monarch Butterfly | Invertebrates | 0.25–0.75 g (0.009–0.026 oz) | adults; about 0.5 g on average |
| Moon Jellyfish | Invertebrates | — | |
| Moose | Mammals | 200–700 kg (440–1,540 lb) | adults; cows 200–490 kg, bulls 380–700 kg; Alaskan moose are the largest |
| Mute Swan | Birds | 8–12 kg (18–26 lb) | adults; males (cobs) average about 11 kg, females (pens) about 9 kg |
| Naked Mole-Rat | Mammals | 30–80 g (1.1–2.8 oz) | workers about 30–35 g; queens 50–80 g |
| Narwhal | Mammals | 800–1,600 kg (1,760–3,530 lb) | adults; females average about 900 kg, males up to 1,600 kg |
| Nile Crocodile | Reptiles | 225–750 kg (500–1,650 lb) | adult males; females are considerably smaller |
| Nine-Banded Armadillo | Mammals | 2.5–6.5 kg (5.5–14 lb) | adults |
| North American Beaver | Mammals | 11–32 kg (24–70 lb) | adults; average about 20 kg |
| North Island Brown Kiwi | Birds | 2–3 kg (4.4–6.6 lb) | adults; females average about 2.8 kg, males about 2.2 kg |
| Northern Cardinal | Birds | 42–48 g (1.5–1.7 oz) | typical adults; extremes range from about 34 to 65 g |
| Ocean Quahog | Invertebrates | roughly 100–300 g (3.5–10.5 oz) | approximate live weight of adults including the shell; varies with size and population |
| Ocean Sunfish | Fish | 247–1,000 kg (545–2,200 lb) | adults; the largest exceed 2,000 kg |
| Ocellaris Clownfish | Fish | about 10–25 g (0.35–0.9 oz) | approximate adult weight; females are the largest fish in a group |
| Okapi | Mammals | 200–350 kg (440–770 lb) | adults; females are slightly larger than males |
| Orca | Mammals | 3,000–6,000 kg (6,600–13,200 lb) | adults; females 3,000–4,000 kg, males often over 6,000 kg, with the largest near 10,000 kg |
| Peregrine Falcon | Birds | 0.33–1.5 kg (0.7–3.3 lb) | adults across all subspecies; males 0.33–1 kg, females 0.7–1.5 kg |
| Pig | Mammals | 140–300 kg (310–660 lb) | mature farm breeds; large boars can exceed 350 kg, miniature breeds are far lighter |
| Plains Zebra | Mammals | 175–385 kg (385–850 lb) | adults; stallions are about 10% heavier than mares |
| Platypus | Mammals | 0.7–2.4 kg (1.5–5.3 lb) | adults; males are larger than females |
| Polar Bear | Mammals | 150–700 kg (330–1,540 lb) | adults; females 150–300 kg, males 350–700 kg |
| Pronghorn | Mammals | 35–65 kg (75–145 lb) | adults; bucks 40–65 kg, does 35–48 kg |
| Rabbit | Mammals | 1–7 kg (2–15 lb) | domestic breeds from dwarfs to Flemish Giants; wild European rabbits weigh 1.2–2.5 kg |
| Raccoon | Mammals | 4–9 kg (9–20 lb) | adults; northern animals and males are heavier, and weight peaks in fall |
| Rainbow Trout | Fish | 0.5–3.6 kg (1–8 lb) | adult stream and lake fish; sea-run steelhead and large-lake fish are often much heavier |
| Red Deer | Mammals | 120–240 kg (265–530 lb) | adults; hinds 120–170 kg, stags 160–240 kg; varies greatly by region |
| Red Fox | Mammals | 3–11 kg (6.5–24 lb) | adults; males slightly heavier, northern foxes largest |
| Red Kangaroo | Mammals | 18–90 kg (40–200 lb) | adults; females 18–40 kg, males 55–90 kg |
| Red Panda | Mammals | 3–6.2 kg (6.6–13.7 lb) | adults; males and females are similar in size |
| Red-Bellied Piranha | Fish | 0.5–3.5 kg (1.1–7.7 lb) | most adults are near the low end; about 3.5–3.9 kg is the recorded maximum |
| Red-Eared Slider | Reptiles | 0.5–1.5 kg (1.1–3.3 lb) | adults; females are larger, and big females can exceed 2 kg |
| Red-Eyed Tree Frog | Amphibians | 6–15 g (0.2–0.5 oz) | adults; females are larger and heavier than males |
| Red-Tailed Hawk | Birds | 0.7–1.5 kg (1.5–3.3 lb) | adults; females average about 25% heavier than males |
| Reindeer | Mammals | 80–180 kg (175–400 lb) | adults; females 80–120 kg, males 160–180 kg; large woodland caribou bulls can exceed 250 kg |
| Reticulated Python | Reptiles | 25–75 kg (55–165 lb) | large adults; females are far heavier than males, and exceptional animals exceed 130 kg |
| Ring-Tailed Lemur | Mammals | 2.2–3.5 kg (4.9–7.7 lb) | adults; wild animals average about 2.2 kg, zoo animals are heavier |
| Rock Pigeon | Birds | 238–380 g (8.4–13.4 oz) | adults |
| Ruby-Throated Hummingbird | Birds | 2–6 g (0.07–0.21 oz) | adults; about 3 g normally, up to 6 g when fattened for migration; females are slightly larger |
| Saltwater Crocodile | Reptiles | males 400–1,000 kg (880–2,200 lb); females 80–150 kg (180–330 lb) | adult females 80–150 kg; mature males 400–1,000 kg |
| Scarlet Macaw | Birds | 0.9–1.2 kg (2–2.6 lb) | adults; about 1 kg on average |
| Sea Otter | Mammals | 14–45 kg (31–99 lb) | adults; females 14–33 kg, males 22–45 kg |
| Seven-Spot Ladybug | Invertebrates | roughly 30–45 mg (about 0.001 oz) | adults; approximate, varies with feeding and season |
| Sheep | Mammals | 45–160 kg (100–350 lb) | ewes 45–100 kg, rams 45–160 kg depending on breed |
| Snow Leopard | Mammals | 22–55 kg (49–121 lb) | adults; males are larger, occasionally reaching 75 kg |
| Snowy Owl | Birds | 1.6–3 kg (3.5–6.6 lb) | adults; females are heavier than males |
| Southern Black Widow | Invertebrates | about 1 g (0.035 oz) | adult females, approximate; males weigh only a small fraction of this |
| Sperm Whale | Mammals | 14–45 tonnes (15–50 US tons) | adult females about 14–15 tonnes, adult males about 35–45 tonnes |
| Spotted Hyena | Mammals | 40–86 kg (88–190 lb) | adults; females are about 10% heavier than males |
| Springbok | Mammals | 27–42 kg (60–93 lb) | adults; rams are slightly heavier than ewes |
| Striped Skunk | Mammals | 1.8–4.5 kg (4–10 lb) | adults; heaviest in fall, males slightly larger |
| Swordfish | Fish | 70–300 kg (150–660 lb) | adults; females are much larger, and the maximum is about 650 kg |
| Tasmanian Devil | Mammals | 4–12 kg (9–26 lb) | adults; males average about 8 kg, females about 6 kg |
| Thomson's Gazelle | Mammals | 15–35 kg (33–77 lb) | adults; males 20–35 kg, females 15–25 kg |
| Tiger | Mammals | 75–260 kg (165–575 lb) | females 75–170 kg, males 100–260 kg; Bengal and Amur tigers are largest, Sumatran smallest |
| Tiger Shark | Fish | 385–635 kg (850–1,400 lb) | adults; exceptional females exceed 900 kg |
| Toco Toucan | Birds | 500–876 g (1.1–1.9 lb) | adults; males are slightly larger |
| Tuatara | Reptiles | 0.5–1 kg (1.1–2.2 lb) | adults; females about 0.5 kg, males up to about 1 kg |
| Veiled Chameleon | Reptiles | 90–200 g (3–7 oz) | adults; females 90–120 g, males 100–200 g |
| Walrus | Mammals | 400–1,700 kg (880–3,750 lb) | adults; Pacific females 400–1,250 kg, Pacific males 800–1,700 kg; Atlantic walruses are smaller |
| Wandering Albatross | Birds | 6–12 kg (13–26 lb) | adults; males are about 20% heavier than females |
| West Indian Manatee | Mammals | 400–600 kg (880–1,320 lb) | typical adults; the largest exceed 1,500 kg |
| Western Diamondback Rattlesnake | Reptiles | 1.8–2.7 kg (4–6 lb) | average-sized adults; very large specimens can reach about 6.7 kg |
| Western Gorilla | Mammals | 68–180 kg (150–400 lb) | adults; females 68–90 kg, silverback males 136–180 kg |
| Western Honey Bee | Invertebrates | about 100 mg (0.004 oz) | workers; queens and drones weigh roughly twice as much |
| Whale Shark | Fish | about 9,000–18,000 kg (20,000–40,000 lb) | large adults; estimates, because very few have ever been weighed |
| White Rhinoceros | Mammals | 1,700–2,400 kg (3,750–5,290 lb) | adults; females average about 1,700 kg, males about 2,300 kg; exceptional bulls reach 3,600 kg |
| White-Tailed Deer | Mammals | 40–135 kg (90–300 lb) | adults; does 40–90 kg, bucks 70–135 kg; northern deer are largest |
| Wild Boar | Mammals | 50–100 kg (110–220 lb) | typical European adults; boars in eastern Europe and northeast Asia can exceed 200 kg |
| Wild Turkey | Birds | 2.5–11 kg (5.5–24 lb) | adults; hens 2.5–5.4 kg, toms 5–11 kg |
| Wolverine | Mammals | 8–18 kg (18–40 lb) | adults; males 11–18 kg, females 8–12 kg |
| Yellow Fever Mosquito | Invertebrates | about 1–2.5 mg (under 0.0001 oz) | unfed adults, approximate; a female can roughly double or triple her weight with a blood meal |