Pig Gestation Calculator

How to Use the Pig Gestation Calculator

Whether you keep a herd of sows or a single pet potbelly, the timing is the same. The calculator counts forward from the breeding date using the 114-day average and shows the full farrowing window plus what to do at each stage.

1. Enter the breeding date. Use the day the sow was served or inseminated. If she was with the boar for several days, use the first service for the earliest possible date.
2. Calculate. You get the earliest (day 111), expected (day 114), and latest (day 115) farrowing dates.
3. Follow the stage guide. The result tells you where she is today and what to prepare next.

How Long Are Pigs Pregnant?

Pigs are pregnant for about 114 days, famously remembered as 3 months, 3 weeks, and 3 days. The normal range is 111 to 115 days, one of the tightest of any farm animal, which is why farrowing dates are so easy to predict.

Gestation barely changes with body size, so a 90-kilogram potbelly pet and a 250-kilogram commercial sow both carry for roughly the same 114 days. Larger litters can arrive a day early, and gilts having their first litter sometimes run a day or two late. A sow still not farrowing by day 116 should be checked by a vet.

Pig Gestation Chart by Stage

The chart below breaks the 114 days into practical stages so you know what is happening and what to do.

Signs a Sow Is About to Farrow

The most dependable sign is milk. Once you can express milk from the teats, farrowing usually follows within about 12 hours.

• Milk let-down: Milk can be squeezed from the teats, the clearest 24-hour warning.
• Udder and vulva swelling: The udder firms up and the vulva enlarges and reddens.
• Nest-building: Even on concrete, a sow will root, arrange bedding, and become restless.
• Off feed: Appetite drops in the final day.
• Restlessness and lying down: She will settle on her side as contractions begin.

Piglets normally arrive every 15 to 20 minutes. Call your vet if the sow strains hard for 45 to 60 minutes with no piglet, if more than an hour passes between piglets while more are clearly due, or if she seems exhausted or distressed.

Farrowing for Pet Mini and Potbelly Pigs

Pet pig owners face the same 114-day timeline but a few different practicalities. Litters are usually smaller, often 4 to 8 piglets, and a house pig will still try hard to build a nest, so give her a quiet, bedded space away from foot traffic.

If you did not plan the litter, this is a good moment to think ahead: an intact pet pig can breed again quickly, and unplanned litters are hard to rehome. Once the piglets arrive, our Mini Pig Weight Guide shows how big they are likely to get, and the Homestead Pets hub links the rest of our small-livestock tools.