Swine gestation calculator.
Find out when your pig is due. Enter the breeding date and the calculator estimates the due date from the average pig gestation, with the earliest and latest dates too.
Breeding date
LivePig gestation lasts about 111 to 118 days, averaging near 114. The due date is the breeding date plus the average gestation; the range gives the earliest and latest.
Estimated farrowing date
Sep 23, 2026
based on average gestation
An estimate based on average pig gestation; individual animals vary. Not veterinary advice. Calculations run in your browser; nothing you enter is stored.
How it works
Counting from breeding
Pig gestation lasts about 111 to 118 days from breeding, about three months, three weeks and three days, with an average near 114 days. The calculator adds the average to the breeding date to estimate the due date, and the 111 to 118 day range gives the earliest and latest you should expect piglets.
The 114-day average follows the classic three months, three weeks and three days rule; litter size and breed shift it slightly. Treat the due date as a window of a few days rather than a single fixed day.
Reference
Gestation by animal.
Typical pregnancy lengths for pigs and other common animals, for comparison.
| Animal | Gestation |
|---|---|
| Sheep | 144 to 152 days |
| Goat | 145 to 155 days |
| Pig | 112 to 120 days |
| Cow | 279 to 287 days |
| Horse | 320 to 370 days |
| Llama | 330 to 370 days |
The full guide
The complete guide to pig gestation.
How long pigs carry, the stages to expect, and when to get help.
How long are pigs pregnant?
Pig gestation runs about 111 to 118 days from breeding, averaging around 114, or about three months, three weeks and three days. Counting from the breeding date gives the most reliable estimate of when piglets are due.
The 114-day average follows the classic three months, three weeks and three days rule; litter size and breed shift it slightly.
Stages of pregnancy
The first month shows no outward signs. From the second month the sow’s abdomen fills out and the udder line develops, and in the final weeks the piglets can sometimes be felt moving.
Ultrasound from about day 21 to 30 confirms pregnancy on most farms and helps plan farrowing batches.
Preparing for the birth
Move the sow to a clean, disinfected farrowing pen or crate about a week before the due date and adjust feed for late gestation. Provide a warm creep area for the piglets, since newborns chill easily.
Restlessness, nest-building and udder filling in the final day signal that farrowing is near.
When to call the vet
Call a vet if the sow passes about 118 to 120 days, strains over 30 to 45 minutes between piglets, or seems exhausted, since large litters can stall. This tool is for planning only and does not replace veterinary care.
The formula
Date plus
gestation.
The due date is the breeding date plus about 114 days, with piglets normally arriving between 111 and 118 days.
Sheep gestation ›# Pig due date
due = breeding_date + gestation
pig gestation = 111 to 118 days
# average 114 days
breeding + 114 daysQuestions
Pig gestation questions.
How long is a pig pregnant?
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About 111 to 118 days from breeding, averaging around 114 days, about three months, three weeks and three days. The calculator uses this to estimate the due date.
How do I calculate a pig due date?
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Add about 114 days to the breeding date. Enter that date above and the calculator gives the estimated due date plus the earliest and latest.
Can the due date be a few days off?
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Yes. The 114-day average follows the classic three months, three weeks and three days rule; litter size and breed shift it slightly. Treat the result as a window from 111 to 118 days.
When should I contact a vet?
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Contact a vet if the pregnancy runs well past 118 days, if labour stalls without progress, or if the animal seems distressed. A prenatal check is always worthwhile.
Is this swine gestation calculator free?
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Yes. It is completely free with no sign-up, and every calculation runs locally in your browser, so nothing you enter is stored or sent anywhere.
About the developer
Jean Borg
Jean builds and maintains every calculator on freecalculators.pro from Malta, with a focus on tools that are fast, free and show their working. The swine gestation calculator estimates a due date from average pig gestation and is for planning, not veterinary advice.