Pig Farrowing Date Calculator: When Will My Sow Farrow?

Use day 114 as the center of your plan. Individual sows and gilts can farrow a few days earlier or later.

Why Farrowing Dates Matter

An estimated date tells you when to prepare the farrowing area, check equipment, organize supplies, and increase observation. It also helps you plan movement without shifting a heavily pregnant sow at the last minute.

When several females are bred, a calendar shows whether your facilities and schedule can handle the expected group. That matters even in a small herd.

Pig Gestation Period Overview

Pig gestation averages about 114 days. Breed, litter, age, and the individual animal can cause some variation.

Record every service date. If a sow is served more than once during the same heat, keep each date and note which one you use for the estimate. If she returns to heat, update the breeding record instead of leaving the original due date active.

How the Farrowing Date Calculator Works

Pig farrowing date calculator

Enter the service date to get the estimated farrowing date and the watch window.

Breeding date

Enter the service date. The calculator adds 114 days and gives you an estimated farrowing date.

You can create a working watch window from about day 112 through day 116. Your veterinarian or production protocol may use a different window based on herd history.

Pair the date with reminders for facility preparation and animal checks. A due date is most useful when it leads to a clear task.

Example Calculation

Your sow was bred on May 1.

Estimated farrowing date = May 1 + 114 days = around August 23

A day 112 to day 116 planning window runs from about August 21 through August 25.

Begin preparation well before that week. Watch for changes such as nest-building behavior and udder development as the date approaches, but remember that signs vary.

Normal Farrowing Window and Red Flags

A few days of variation around day 114 can be normal. Accurate service records make it easier to tell whether the sow is truly early or late.

Contact a veterinarian if the sow appears ill, has severe distress, shows abnormal discharge, or has active labor without normal progress. Ask for a herd-specific farrowing plan before the due window. That plan should cover who to call, what information to provide, and what you can safely do while help is on the way.

Do not rely on a date calculator to decide whether an emergency exists.

Manage Your Breeding Sows in Pen & Pasture

Pen & Pasture keeps service dates, expected farrowing dates, sire information, pregnancy notes, and litter results on the sow's record. The calendar lets you see which females are due and when your farrowing spaces may overlap.

After farrowing, add the actual date and piglet outcome. Consistent records help you review sow performance and plan the next breeding cycle with real herd data.