Hamster Gestation Period: How Long Is a Hamster Pregnant?

How long is a hamster pregnant?

A hamster carries her pup for an average of 16 days, or about 0 months and 2 weeks. Counting from the breeding date, birthing is normal anywhere from day 15 to day 18.

Key checkpoints across the 16-day hamster gestation, measured in days from breeding:

Estimate your hamster's birthing date

Enter the breeding date for an estimated birthing date at 16 days.

Open the full Hamster gestation calculator

Hamster gestation stages, month by month

Signs a hamster is pregnant

• Noticeable weight gain and a pear-shaped belly from about day 10 — with a 16-day pregnancy this is often the first clue
• Heavy food hoarding and dragging bedding into one corner
• Nipples become more prominent and visible through the coat
• She becomes defensive about being handled or having the cage opened

Signs of approaching birthing

• Intense nest building in the final day or two
• Restlessness and stretching on the day, with birth usually happening overnight
• Contact your vet if labour stalls, if the animal strains without progress, or if there is abnormal discharge before birthing begins.

What affects hamster gestation length

• Species matters more than anything else: Syrian hamsters deliver in about 16 days, Campbell's dwarfs in 19 to 20, Chinese hamsters in 21 and Roborovskis in 23 to 24.
• Sixteen days is one of the shortest gestations of any mammal, so a hamster pregnancy can be over before an owner is certain it started.
• Disturbing the nest in the first week after birth is the classic cause of a mother eating or abandoning her pups — no cleaning, no handling, no photographs.
• Syrian hamsters are strictly solitary: the male must be removed the moment mating is over, and pups must be separated by sex by about five weeks or they will breed with each other.
• A dwarf female can fall pregnant again within a day of giving birth if the male is left in, which exhausts her and often kills both litters.
• Females can be fertile from four weeks old but are far too immature to carry safely; responsible breeding waits until at least four months.

Hamster gestation chart

Every fifth breeding date across the year with the matching birthing date, calculated at 16 days. Find the row closest to the date the hamster was served; because normal gestation spans 15 to 18 days, plan for a window of a few days either side. Filter by month, or print the chart for the barn wall or breeding record: navigation, buttons and adverts are hidden on paper.

Hamster gestation length by breed

Sources for hamster gestation figures

Figures on this page are drawn from laboratory and companion rodent reference works, hamster species reproduction data and small mammal veterinary guidance, and checked against the references below. Averages describe healthy animals under normal management; individual animals vary, and nothing here replaces advice from your vet.

• Merck Veterinary Manual — reproduction and pregnancy chapters by species
• Laboratory animal science references on rodent reproduction