Pig Gestation Calculator
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.
How to use the pig gestation calculator
- 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. Refine the inputs. Pick the breed so the calculator uses the right average gestation length.
- 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.
Calculate a piglet due date
Estimated farrowing date
Tuesday, 5 January 2027
Earliest
3 Jan 2027
Latest
7 Jan 2027
0 of 115 days elapsed
Milestone timeline
| Day | Milestone | Date |
|---|---|---|
| 21 | Sow returns to heat if she did not hold to service | 3 Oct 2026 |
| 28 | Ultrasound scan confirms pregnancy | 10 Oct 2026 |
| 75 | Lift the ration: most piglet growth starts now | 26 Nov 2026 |
| 105 | Wash the sow, treat for parasites and move her to the farrowing pen | 26 Dec 2026 |
| 112 | Nest-building begins; earliest normal farrowing | 2 Jan 2027 |
| 115 | Expected farrowing | 5 Jan 2027 |
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.
| Breeding date | Expected farrowing date |
|---|---|
| 12 Sept 2026 | 4 Jan 2027 |
| 19 Sept 2026 | 11 Jan 2027 |
| 26 Sept 2026 | 18 Jan 2027 |
| 3 Oct 2026 | 25 Jan 2027 |
| 10 Oct 2026 | 1 Feb 2027 |
| 17 Oct 2026 | 8 Feb 2027 |
| 24 Oct 2026 | 15 Feb 2027 |
| 31 Oct 2026 | 22 Feb 2027 |
| 7 Nov 2026 | 1 Mar 2027 |
| 14 Nov 2026 | 8 Mar 2027 |
| 21 Nov 2026 | 15 Mar 2027 |
| 28 Nov 2026 | 22 Mar 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.
| Breed | Average days | Difference |
|---|---|---|
| Average | 115 | +1 days |
| Large White | 114 | — |
| Landrace | 114 | — |
| Duroc | 115 | +1 days |
| Hampshire | 115 | +1 days |
| Berkshire | 116 | +2 days |
| Tamworth | 116 | +2 days |
| Gloucestershire Old Spots | 116 | +2 days |
| Kunekune | 117 | +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.