About Sheep & Goat Tools

Sheep & Goat Tools is a small, independent website that makes simple calculators for people who keep sheep and goats: commercial shepherds, smallholders, homesteaders and 4-H and FFA families. Every tool does one job, works on a phone in the barn, and gives you a straight answer.

This site is new. The domain name sheepgoatmarketing.org was used years ago by a university sheep and goat marketing program. That program has ended, and this site is not connected to it, or to any university, breed society or company.

How the calculators work

• Lambing date = breeding date + gestation length. The default is 147 days, the figure used by most extension services. The normal window is 142–152 days.
• Breed lengths are typical averages reported for each breed by breed associations, extension guides and breeders. Individual flocks vary by a day or two either way.
• Heat cycle = 17 days, used to split a joining into lambing groups.
• Scanning window = days 45–90 after mating. Late-pregnancy feeding starts 6 weeks before lambing. Booster and crutching 2–4 weeks before. Lambing checks from 10 days before.
• Dates are counted in whole calendar days, with leap years handled.

Sources

• Susan Schoenian, Sheep 201: A Beginner’s Guide to Raising Sheep, University of Maryland Extension (gestation length, reproduction, lambing signs).
• American Dorper Sheep Breeders’ Society, gestation calculator (Dorper and White Dorper average 145 days).
• Merck Veterinary Manual, management of reproduction in sheep.
• Penn State Extension and University of Kentucky sheep and goat resources (late-gestation nutrition, pre-lambing vaccination).

Not veterinary advice

The calculators give planning dates based on averages. They can’t tell you whether a ewe is healthy or how her lambing is going. For any problem with a pregnancy or a lambing, call your veterinarian.

Found a mistake?

If a date looks wrong, or your breed is missing, please tell us. Corrections are fixed quickly and noted on the page.

Updated November 2026 · How we calculate