Pig Gestation Calculator

Enter the breeding date to get the farrowing date (the '3 months, 3 weeks, 3 days' rule), heat-check dates and when to move her to the farrowing pen.

The day the sow was bred or inseminated, or the day the boar went in.
For pasture breeding. Widens the window.

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Pig Gestation Calculator · HerdMath

How it works

Pigs have a short, very predictable pregnancy: about 114 days, usually remembered as 3 months, 3 weeks and 3 days. Most sows farrow within a couple of days of that date. Heritage and Kunekune pigs can run a day or two longer.

How to use it

Enter the day she was bred or inseminated. If the boar stayed with her for a few days, add the day he was removed.

Reference chart

TypeTypical gestation
Average (most breeds)114 days
Kunekune116 days
Pot-bellied pig114 days

Frequently asked questions

How long is a pig pregnant?

About 114 days, or 3 months, 3 weeks and 3 days. The normal range is about 111 to 117 days.

How many piglets does a sow have?

Commercial sows often have 10–14 piglets. Heritage and Kunekune pigs usually have smaller litters, and first-time gilts have fewer than mature sows.

What are the signs a sow is about to farrow?

Nesting (gathering bedding), restlessness, a swollen vulva and milk you can express from the teats. Milk usually means farrowing within about 24 hours.

How soon can a sow be bred after farrowing?

Sows usually come back into heat 3–7 days after the piglets are weaned. Breeding is normally timed to that heat.

Figures are typical values from university extension and breed-association guidance. Estimates only. Individual animals vary — confirm pregnancy and health questions with your veterinarian. Last reviewed 2026-09-18.