Guinea Pig Gestation Calculator – Cavy’s Pregnancy

Guinea Pig Gestation Calculator

This guinea pig gestation calculator is an online or app-based tool that allows owners to estimate the birth due date when their sow becomes pregnant.

By counting forward the average gestation’s length of 63-68 days from the date of successful breeding, the calculator can predict a due date range.

This allows cavy’s owners to prepare for the impending birth, making sure they have supplies for care of mom and babies.

It also helps narrow down the watch period for signs of imminent labor approaching, such as nesting behavior, appetite changes, and vulva swelling.

Using a cavy’s gestation calculator removes the guesswork and stress of not knowing when pups may arrive.

Guinea Pig Gestation Calculator

Guinea Pig Pregnancy Calculator
Guinea Pig Pregnancy Calculator

Use below pet gestation calculator to find calculate guinea pig’s pregnancy period accurately.

How to Calculate Guinea Pig Gestation

To estimate the due date, you’ll need to know the first day your sow was bred. This is called the date of service or mating.

Step 1) Mark the date your sow was successfully bred. You may need multiple days of re-breeding to ensure pregnancy.

Step 2) Count forward the average gestation period from that date:

  • 63 days for a due date estimate
  • Up to 68 days for the latest possible due date

Step 3) Mark a range on your calendar for the expected delivery window. Be prepared for babies to arrive a few days earlier or later than your estimate.

You can use an online guinea pig gestation calculator for convenience. Simply enter the first breeding date and it will calculate the estimated due date for you.

Average Guinea Pig Gestation Period

Guinea Pig Gestation Period
Guinea Pig Gestation Period


The normal gestation period for guinea pig’s ranges from 59-72 days. The average pregnancy length is:

  • 63 days (at the short end of the range)
  • 68 days (at the long end of the range)

So a typical guinea pig pregnancy lasts 63-68 days from the date of breeding to delivery. Anything less than 59 days or more than 72 days would be considered an abnormal length gestation.


In weeks, the average guinea pig pregnancy lasts:

  • 9 weeks (63 days)
  • 9.7 weeks (68 days)

So you can estimate an average pregnancy of 9-10 weeks from breeding to birth.


To convert the weeks into months:

  • 2.1 months (9 weeks)
  • 2.3 months (9.7 weeks)

Rounding to whole months, the typical guinea pig gestation length is 2-2.5 months.

So in summary, the normal guinea pig pregnancy lasts 63-68 days, or 9-10 weeks, or 2-2.5 months on average from the date of successful breeding to delivery of pups. Knowing the averages helps estimate when to expect babies using a gestation calculator. Monitor mom closely as she nears the due date!

How to tell when a guinea pig is about to give birth?

How to tell when a guinea pig is about to give birth
How to tell when a guinea pig is about to give birth

In the final 24-48 hours before delivery, a pregnant sow will demonstrate several telling behaviors and physical symptoms.

She will appear extremely restless, repeatedly entering and exiting the nest or pacing the cage.

Appetite diminishes severely or ceases completely as labor nears. The pregnant belly swells up tightly, nipples become enlarged and vulva swells.

Discharge may be visible. The sow may isolate herself, grunting or crying out uncomfortably. Pelvic and hip muscles relax, causing noticeable hair loss around the hips and hind legs.

Nesting behaviors like burrowing will intensify. Once these signs are all observed, birth is imminent within hours. Prepare a quiet, warm environment for the sow and monitor closely.

When can you tell a guinea pig is pregnant?

Early signs of guinea pig pregnancy become noticeable around 3-4 weeks gestation. The most obvious is enlargement and reddening of the nipples as mammary glands prepare for nursing.

Slight abdominal swelling may be visible, though the belly only becomes obviously distended around weeks 5-6. Behaviorally, the sow may act more restless or vocal.

In the last weeks of pregnancy, abdominal enlargement is extreme, movement slows, and nesting behaviors like bedding rearrangement intensify. Veterinary exams or abdominal palpation can confirm pregnancy earlier on.

How far apart do guinea pigs give birth?

During delivery, guinea pigs usually have 10-30 minutes between birthing each pup. Some sows have longer intervals up to 2 hours between babies, which is still normal.

Larger litters generally have shorter intervals between pup births. The entire birthing process takes 2-6 hours on average, though it can last up to 12 hours for a very large litter of 6+ pups.

As long as the sow is resting comfortably between births and no obvious issues seen, these intervals are normal.

How long do guinea pigs get pregnant?

The normal gestation period for guinea pigs ranges from 59-72 days, averaging around 63-68 days. This is one of the shortest pregnancies among rodents and small pets.

For comparison, chinchillas are 111 days pregnant and hamsters just 16-18 days.

Anything shorter than 59 days or longer than 72 days would be an abnormally short or long pregnancy for a guinea pig and warrant a vet visit.

Knowing the normal term helps estimate due dates.

How many babies do guinea pigs have at a time?

Guinea pig litter sizes range from 1-8 pups, though 2-4 is average. Young sows under a year old tend to have larger litters around 4-5 babies.

Older sows over 2 years old typically have smaller litters of just 1-3 pups. Factors like sow size, age, breed, and individual fertility impact litter size.

As long as babies are healthy, smaller litters of 1-2 are perfectly normal and not a cause for concern.

Do guinea pigs get periods?

No, guinea pigs do not menstruate or have periods. Females experience an estrous cycle every 14-19 days when they come into heat.

For 8-10 hours of that cycle, ovulation occurs and the sow can become pregnant if bred.

There is no visible bleeding or discharge during this cycle, though increased aggression may be noticed around ovulation.

Without pregnancy, the cycle simply repeats again in two weeks. Guinea pigs reabsorb the uterine lining rather than shedding it like in menstruating species.

Common Questions

How many babies do guinea pigs have in their first litter?

Guinea pigs tend to have larger litters for their first pregnancy compared to subsequent litters. Here are some details on first litter sizes for guinea pigs:

First Litter Size

  • For young sows under 1 year old having their first litter, it is common to have 3-5 babies.
  • Many first-time guinea pig moms will have a larger than average litter of 4-6 pups.
  • Litters as large as 6-8 babies are possible for a young sow’s first pregnancy.

Subsequent Litters

  • For later litters after the first one, sows generally have smaller litter sizes of 2-4 pups on average.
  • Older adult sows over 2-3 years old may only have 1-3 babies per litter.

The larger first litter size is thought to be due to the sow’s peak fertility and body condition when young. As sows age, their litter sizes tend to decrease.

Other Factors

Guinea pig litter size can also be influenced by:

  • The breed (some have tendencies toward larger or smaller litters)
  • The sow’s overall health and nutrition status
  • Genetics and the sow’s mother’s typical litter sizes

So while averages are 2-4 pups, it’s not unusual at all for a young guinea pig mom to have 5-8 babies for her very first litter before numbers taper off. Being prepared for a larger litter the first time around is wise. Proper care is important with such a vibrant start to the sow’s breeding career!

How do I know if my guinea pig is pregnant?

Signs of pregnancy include belly swelling, mammary gland development, increased appetite, nesting behavior and less social interaction in the later weeks. Pregnancy is certain if you visually confirm breeding.

What should I do to prepare for baby guinea pigs?

  • Calculate the due date using a gestation calculator.
  • Prepare a nesting area with plentiful hay.
  • Remove hazards like high shelves and wire flooring.
  • Read up on proper newborn guinea pig care.
  • Have supplemental formula and syringes on hand.
  • Set up a second cage to separate boars from sows by 3-4 weeks old.

Why did my guinea pig only have 1 or 2 babies? Is that normal?

Yes, small litters of 1-2 pups are perfectly normal in guinea pigs. Older sows in particular tend to have fewer babies per litter. As long as the babies are healthy, there is no cause for concern. Focus on providing great care rather than worrying about litter size.

My guinea pig hasn’t given birth yet at 70 days pregnant. What should I do?

Contact your exotic veterinarian if your sow goes more than 72 days without giving birth. They can do an examination and determine if intervention is needed. Guinea pigs rarely go more than a couple days past 72 days gestation.

How can I tell if a newborn guinea pig is healthy?

Check that the pup is fully formed, has all limbs/digits, a rounded belly, bright eyes and pink skin. Listen for clear breathing and crying sounds. Healthy newborns should be very active. Weigh daily – they should gain weight steadily. Any deformities, weakness or weight loss are bad signs requiring vet care.

Expert Care Tips

  • Track the sow’s weight weekly during pregnancy. She should gain 200-300g total.
  • Schedule a vet visit for a prenatal checkup during mid-late pregnancy.
  • Increase the sow’s diet with extra hay, veggies and pellets during pregnancy.
  • Remove the boar once the sow is visibly pregnant to prevent repeated litters.
  • Provide multiple hideys, one per sow, to reduce stress.
  • Clean the cage meticulously right before delivery day.
  • Have emergency supplies ready like formula, syringes, heating pad.
  • Handle newborns for only brief daily weigh-ins during the first week.
  • Check each pup’s milk band daily to ensure they are nursing.
  • Separate all boars from nursing sows no later than 3-4 weeks old.
  • Consult an exotics vet if issues arise during pregnancy or with newborns.


Estimating due dates with a guinea pig gestation calculator can help you prepare for the big arrival. Normal pregnancies last 59-72 days on average. Provide excellent care during pregnancy and baby guinea pig infancy for the best outcomes. With attentive fostering from mom and handling by a caring owner, the pups will thrive into lively, entertaining young guinea pigs bringing joy to your home. Enjoy the exciting journey of your herd growing!

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