Guinea Pig Pregnancy Calculator — Gestation Due Date

Formula

How this is calculated

Guinea pig (cavy) pregnancies are comparatively long for rodents: the normal gestation range is 59–72 days, with most litters arriving around day 63–68. Larger litters (3–4 pups) tend to be born earlier; smaller litters of one or two pups often run longer. The default gestation of 68 days is a widely used midpoint estimate — adjust it to match your vet's assessment or the sow's prior litter history.

The calculator subtracts the days elapsed since mating from the expected gestation length to give the days remaining. The progress bar fills proportionally to show where you are in the pregnancy cycle. If the elapsed days exceed the gestation period, the result switches to show how many days overdue the birth is — at that point close monitoring and a vet consultation are advisable.

Note that the exact mating date can be hard to determine unless guinea pigs are housed separately and reunited for controlled mating. If the precise date is uncertain, use the midpoint of the suspected mating window and update when better information is available. Stress, poor nutrition, and very large or very small litters can all shift the actual birth date outside the expected range.