Animal Gestation Calculator

Pig Gestation Calculator

Last updated

A pig's gestation period is about 114 days, or roughly 3 months and 3 weeks, though it ranges from 112 to 116 days depending on breed and individual animal.

Calculate a piglet due date

What do you know?

Estimated farrowing date

Saturday, 20 February 2027

Earliest

18 Feb 2027

Latest

22 Feb 2027

115 days remaining0% complete

0 of 115 days elapsed

Milestone timeline

Key Pig pregnancy milestones with calculated calendar dates
DayMilestoneDate
21Sow returns to heat if she did not hold to service18 Nov 2026
28Ultrasound scan confirms pregnancy25 Nov 2026
75Lift the ration: most piglet growth starts now11 Jan 2027
105Wash the sow, treat for parasites and move her to the farrowing pen10 Feb 2027
112Nest-building begins; earliest normal farrowing17 Feb 2027
115Expected farrowing20 Feb 2027

What to do next

How to use the pig gestation calculator

  1. 1. Choose what you know. Enter the breeding date to get a due date, or switch to the target due date mode to work backwards to the breeding date you need.
  2. 2. Refine the inputs. Pick the breed so the calculator uses the right average gestation length.
  3. 3. Plan around the range. Use the earliest and latest dates and the milestone timeline to schedule checks, feed changes and preparation of the farrowing area.

How long is a pig's gestation period?

The average is 114 days from breeding to farrowing, about 3 months and 3 weeks. Anything between 112 and 116 days is normal, and a typical litter is 8-12 piglets. Treat the calculated date as the middle of that window rather than a fixed appointment.

Pig gestation table: breeding date to farrowing date

Breeding dates one week apart with the matching farrowing date at 114 days.

Twelve sample Pig breeding dates and their calculated due dates
Breeding dateExpected farrowing date
28 Oct 202619 Feb 2027
4 Nov 202626 Feb 2027
11 Nov 20265 Mar 2027
18 Nov 202612 Mar 2027
25 Nov 202619 Mar 2027
2 Dec 202626 Mar 2027
9 Dec 20262 Apr 2027
16 Dec 20269 Apr 2027
23 Dec 202616 Apr 2027
30 Dec 202623 Apr 2027
6 Jan 202730 Apr 2027
13 Jan 20277 May 2027

How breed changes the farrowing date

Selecting a breed swaps the average the calculator uses, which can move the farrowing date by more than a week.

Pig breeds and their average gestation length in days
BreedAverage daysDifference
Average115+1 days
Large White114—
Landrace114—
Duroc115+1 days
Hampshire115+1 days
Berkshire116+2 days
Tamworth116+2 days
Gloucestershire Old Spots116+2 days
Kunekune117+3 days

Working backwards from a target farrowing date

If you want piglets on the ground in a particular week, switch the calculator to target date mode and enter the date you are aiming for. It subtracts 114 days to give the breeding date to book, plus the earliest and latest service dates that still land inside your window.

Pig gestation calculator FAQs

How do I calculate a pig due date?

Enter the breeding or mating date and the calculator adds the average pig gestation of 114 days. It also shows the earliest (112 days) and latest (116 days) dates that are still normal.

Should I use the first or last mating date?

If mating happened over several days, run the calculator for the first and the last date. The piglet is most likely to arrive between the earliest result of the first date and the latest result of the last date.

Can I work out when to breed for a target pig due date?

Yes. Switch to target due date mode and enter the date you want; the calculator subtracts 114 days to give the breeding date, plus the earliest and latest breeding dates that still fit.

How accurate is the pig due date calculator?

It gives a planning estimate from published averages. Most births fall inside the 112–116 day window shown, but ask a vet to confirm the pregnancy and check anything outside that range.

Does the breed change the pig due date?

It can. Pick the breed in the calculator and it uses that breed's average instead of the species average, which moves the due date by a few days for some breeds.

More gestation pages

Livestock gestation chart