Sheep Gestation Calculator
Editable planning estimates • breed does not determine an exact due date.
Breeding & Care Inputs
Lambing & Care Calendar
Gestation Progress
—Care illustration • actual lambing may occur earlier or later.
Flock Care Timeline
Care dates shift when you change the lambing estimate; scan follows breeding day 0. Milestones are arranged chronologically; the rail is schematic.
Formula & Planning Notes
Lambing date=breeding date + gestation days
Pre-lambing care date=estimated lambing − lead time
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Scan window: breeding + 45–60 days. Booster planning window: estimated lambing − 42 to 28 days. If the ram ran with the flock for several days, one breeding date cannot represent every ewe’s lambing window.
Frequently Asked Questions
How accurate is the expected date?
147 days is an average planning estimate. Gestation varies by ewe, breed, litter and circumstances. The 146/147/150-day presets are editable examples, not guaranteed breed-specific dates. A countdown does not confirm pregnancy or that lambing has occurred.
When should I arrange a pregnancy scan?
The example schedule uses day 50 within a day 45–60 planning window. SDSU describes day 45–65 as a preferred fetal-counting window; exact timing and technique should be agreed with your scanning provider. A calendar cannot determine litter size.
What does Download .ics do?
It saves a calendar file with six all-day planning events for breeding, pregnancy scan, nutrition review, booster, pen preparation and estimated lambing. Import the file into your calendar application; nothing is added to an external calendar automatically.
Are the vaccine and nutrition dates the same?
They are separate settings. The example booster is five weeks before estimated lambing, while the nutrition review is six weeks before. Follow your veterinarian’s product-specific vaccination plan. The feeding review does not automatically prescribe supplements or a ration.
What does this calculator calculate?
The estimated lambing date, days remaining, gestation progress, breeding-based scan dates and lambing-based care dates. It generates a planning timeline and a downloadable calendar.
Which inputs and formula are used?
Enter a known breeding date, whole gestation days and the selected care lead times. Breeding is day 0. Add gestation days for lambing; subtract lead days or weeks from estimated lambing for pre-lambing care.
Why might my date differ from another calculator?
A different gestation estimate or day-1 counting convention can shift the result. Uncertain mating dates or an extended ram-exposure period also widen the practical lambing window. This tool uses whole calendar days, with breeding as day 0.
Does the calendar update automatically?
Yes. Breed presets, numeric entries and care selections update all displayed dates. The countdown uses your browser’s local date. Download a fresh .ics file after changing the plan; importing behavior and duplicate handling depend on your calendar app.
Sheep Gestation Calculator Calculate the expected lambing date based on the breeding date. Average ovine gestation is 147 days. — free online calculator.