Animal Gestation Calculator

Animal Gestation Chart

Average gestation length for every species on the site, with the normal range, the equivalent in months and typical litter size. Sort any column or filter by category.

Gestation length by species, sortable and filterable
RangeMonthsLitter size
Virginia opossum gestation calculator1312–140.4 months8-9 joeysWild animals
Hamster gestation calculator1615–180.5 months6-8 pupsRodents and small pets
Mouse gestation calculator2019–210.7 months5-8 pupsRodents and small pets
Rat gestation calculator2221–230.7 months6-12 pupsRodents and small pets
Gerbil gestation calculator2524–260.8 months4-8 pupsRodents and small pets
Rabbit gestation calculator3128–331.0 months4-12 kitsPets
Red kangaroo gestation calculator3330–361.1 months1 joeyWild animals
Ferret gestation calculator4238–441.4 months6-8 kitsRodents and small pets
Grey squirrel gestation calculator4440–451.4 months2-4 kitsWild animals
Red fox gestation calculator5249–551.7 months4-6 kitsWild animals
Dog gestation calculator6358–682.1 months1-12 puppiesPets
Cat gestation calculator6461–672.1 months3-5 kittensPets
Guinea pig gestation calculator6859–722.2 months2-4 pupsRodents and small pets
Tiger gestation calculator10593–1123.4 months2-4 cubsWild animals
Lion gestation calculator110105–1153.6 months2-4 cubsWild animals
Chinchilla gestation calculator111105–1183.6 months1-3 kitsRodents and small pets
Pig gestation calculator114112–1163.7 months8-12 pigletsLivestock
Sheep gestation calculator147144–1524.8 months1-2 lambsLivestock
Goat gestation calculator150145–1554.9 months1-3 kidsLivestock
White-tailed deer gestation calculator200187–2226.6 months1-2 fawnsWild animals
Grizzly bear gestation calculator235180–2507.7 months1-3 cubsWild animals
Chimpanzee gestation calculator237230–2407.8 months1 infantWild animals
Hippopotamus gestation calculator240225–2507.9 months1 calfWild animals
Gorilla gestation calculator257250–2708.4 months1 infantWild animals
Human280259–2949.2 months1 babyWild animals
Cow gestation calculator283279–2929.3 months1 calfLivestock
Water buffalo gestation calculator310300–32010.2 months1 calfLivestock
Horse gestation calculator340320–37011.2 months1 foalLivestock
Blue whale gestation period340330–36011.2 months1 calfWild animals
Alpaca gestation calculator345335–35511.3 months1 criaLivestock
Llama gestation calculator350330–36511.5 months1 criaLivestock
Donkey gestation calculator365340–39012.0 months1 foalLivestock
Dolphin gestation calculator365340–38012.0 months1 calfWild animals
Zebra gestation calculator375360–39012.3 months1 foalWild animals
Manatee gestation calculator380365–40012.5 months1 calfWild animals
Camel gestation calculator395390–41013.0 months1 calfLivestock
Giraffe gestation calculator430400–46014.1 months1 calfWild animals
Walrus gestation calculator460450–48015.1 months1 calfWild animals
White rhinoceros gestation calculator490480–50016.1 months1 calfWild animals
Sperm whale gestation period530480–59017.4 months1 calfWild animals
Asian elephant gestation calculator617600–64020.3 months1 calfWild animals
African elephant gestation calculator645640–66021.2 months1 calfWild animals

https://animalgestationcalculator.com

How to read this chart

The average days column is the figure the calculators use, and it is the midpoint of normal births rather than a deadline. The range column shows the window in which healthy young usually arrive, so plan for the earliest date in that window. Months are an approximation at 30.44 days per month and are there for quick conversation, not for scheduling. Litter size explains part of the range: species carrying several young tend to give birth slightly earlier than the average suggests, while a single large offspring often runs a few days late.

Longest and shortest gestation periods

The longest gestation on this chart belongs to the african elephant gestation period at 645 days, and the shortest to the virginia opossum gestation period at 13 days. Long gestations produce young that stand and follow the mother within hours, which is essential for grazing animals in the open. Short gestations produce blind, helpless young that finish developing in a nest, so the mother invests in nursing rather than in pregnancy.

Gestation chart questions

Which animal has the longest gestation period on this chart?

Of the species listed here the horse is longest at about 340 days, ahead of the cow at 283 days. Across all mammals the African elephant is longest at roughly 645 days.

Which animal has the shortest gestation period?

The rabbit, at about 31 days. Cats and dogs follow at roughly 64 and 63 days, which is why whelping and kindling preparation has to start within weeks of mating.

Why do the figures differ from other gestation charts?

Different sources use different breeds, herd data and starting points. Some count from mating, others from ovulation or embryo transfer, which shifts the average by several days.

What does the range column mean?

It is the window in which a healthy birth normally happens for that species, not a margin of error. Plan for the earliest date rather than the average.

Can I print this gestation chart?

Yes. Use the print button above the table and the page prints the heading, the full table and the site address only, with navigation, filters and ads removed.

Every figure is an average from published breed data. Individual animals vary; results are for planning and are not veterinary advice.