Pig Gestation Calculator
Pig gestation calculator using the 114-day average — 3 months, 3 weeks, 3 days. Enter a breeding or AI date for a farrowing window and management milestones.
- 114days avg
- 3-3-3rule of thumb
- ±3day window
Expected farrowing
Tue, December 8, 2026
Window: Dec 5, 2026 – Dec 11, 2026 (±3 days)
Upcoming milestones
- Sep 6, 2026 — Watch for return to estrusIf she cycles again around day 18–24, she may not be settled
- Sep 15, 2026 — Confirm pregnancyUltrasound commonly used around days 24–35
- Oct 30, 2026 — Increase late-gestation nutritionFetal growth accelerates in the final third
- Nov 24, 2026 — Move to farrowing crate / penTypically 5–7 days before due date for close monitoring
Pig gestation calculator (114 days)
Pig gestation calculator math uses the industry average of 114 days — the familiar 3 months, 3 weeks, 3 days rule of thumb. Enter the breeding or AI date above for an expected farrowing date plus an early/late window (±3 days). Switch to reverse mode to back into a breeding date from a target farrowing date.
Sows and gilts still vary. Litter size, parity, and genetics can shift timing by a few days. Plan crate moves and labor with the window, not a single calendar day.
Pig pregnancy timing at a glance
| Measure | Typical value |
|---|---|
| Average gestation | 114 days |
| Rule of thumb | 3 months, 3 weeks, 3 days |
| Normal window | ~111–117 days |
| Estrus cycle | ~21 days |
If a sow returns to heat around day 18–24, she may not be settled. Confirm with ultrasound when your protocol calls for it (often around days 24–35).
Farrowing milestones to plan around
- Days 1–38: implantation and early embryonic loss risk; watch for return to estrus.
- Days 39–76: fetal development; maintain body condition.
- Days 77–114: rapid fetal growth; increase late-gestation nutrition and move to the farrowing area about a week before due date.
Restlessness, nest-building, and milk let-down often appear within a day of farrowing. Have heat lamps, processing supplies, and help lined up before the early window starts.
Related livestock timing tools
If you run mixed species, plan alongside the goat gestation calculator, sheep gestation calculator, and cattle gestation calculator. Financing herd expansion? Try the farm loan calculator.
Frequently asked questions
How long is a pig pregnant?
About 114 days on average — 3 months, 3 weeks, and 3 days. Most sows farrow within a few days of that mark.
Do gilts gestate differently than sows?
Gestation length is similar. Gilts may need closer supervision at farrowing; plan from the 114-day average unless your vet advises otherwise.
Can I plan breeding from a target farrowing date?
Yes. Use reverse mode in the calculator: enter the farrowing date you want and get the breeding date to aim for.