Pig Pregnancy Calculator — Farrowing Due Date (114 Days)

Sow gestation is famously '3 months, 3 weeks and 3 days' — 114 days total (range 112–116). This tight window makes farrowing easy to predict.

Watch for a missed estrus at day 21 post-breeding. Ultrasound from day 21 confirms pregnancy. From day 35, ultrasound can count piglets.

Average modern commercial litter: 10–14 piglets. Heritage breeds: 6–10. Second-parity and later sows typically have larger litters than gilts (first-timers).

7–10 days before expected farrowing (around day 104–107). This reduces stress and allows her to adapt to the environment.

Udder develops days 110–112, vulva swells 24 hours before, nest-building behavior, milk let-down when nipples squeezed, decreased appetite. Farrowing lasts 2–5 hours.