Swine Gestation Calculator
114-day planning default • use herd records to adjust the estimate.
Breeding & Care Inputs
Farrowing & Care Calendar
Gestation Progress
—Care illustration • actual farrowing may occur earlier or later.
Farrowing Care Timeline
Checks follow breeding day 0; pre-farrowing care follows the estimated due date. Milestones are arranged chronologically; the rail is schematic.
Formula & Planning Notes
Farrowing date=breeding date + gestation days
Care date=estimated farrowing − lead time
—
Use a known service date and herd-specific gestation records. The 114-day default is a conventional planning estimate; real gestation can differ. Heritage presets are editable examples, not breed-specific guarantees.
Frequently Asked Questions
Why use 114 days?
114 days is a conventional swine gestation planning estimate, often remembered as “3 months, 3 weeks, 3 days.” Calendar months vary in length, so the calculation adds exactly the selected number of whole days. Adjust the estimate using your herd’s service and farrowing records; it is not a guaranteed due date.
Why are heat check and ultrasound separate?
Monitoring for return to estrus and scanning for pregnancy are different tasks. This tool uses a day-21 heat reminder and a day-28 ultrasound example. Penn State discusses confirmation around days 28–35, while Pork Information Gateway describes real-time ultrasound around days 24–35. Agree timing and any repeat checks with your provider; a reminder does not confirm pregnancy.
What does Download .ics do?
It saves six all-day planning events: breeding, heat check, ultrasound, pre-farrowing health review, pen move and estimated farrowing. Import the file into your calendar app. The calculator does not automatically write to an external calendar.
Does the health review prescribe vaccination or deworming?
No. The default three-week lead time is a review reminder. Vaccine, parasite-control and any supplementation plans depend on herd status, product instructions and veterinary advice. Selecting a date is not a treatment recommendation.
What does the Swine Gestation Calculator calculate?
The estimated farrowing date, remaining days, gestation progress and care reminders. Heat and ultrasound dates follow breeding; health review and pen move dates follow the estimated due date. This is a pig calculator, not a cattle calculator.
Which values should I enter?
Enter a known breeding or service date, gestation estimate and herd-specific care timings. Commercial uses a 114-day example. Heritage initially uses an editable 115-day example within the stated 112–116 planning assumption; Custom accepts 110–120 whole days.
What formula does this calculator use?
Farrowing date = breeding date + gestation days. Care date = estimated farrowing date minus the selected lead days or weeks. Heat and scan dates = breeding date plus selected check day. Breeding is day 0.
Why might my result differ from another source?
Different service dates, gestation assumptions and day-0/day-1 counting conventions can shift the estimate. Adding calendar months for the mnemonic can also differ from adding 114 days. Individual sows may farrow earlier or later than estimated.
Does the result update automatically?
Yes. Dates, presets and care inputs update all results immediately. Countdown uses your browser’s local date. Download a fresh .ics file after changing the plan; duplicate handling when importing is controlled by your calendar app.
Swine Gestation Calculator Calculate the expected farrowing date based on the breeding date. Swine gestation averages 114 days (3 months, 3 weeks, 3 days). — free online calculator.