How long is a cow pregnant?
A cow carries a calf for about 283 days, a little over nine months. Breed shifts that number: British breeds like Angus run shorter, while Continental and Zebu breeds run longer. Bull calves are typically carried one to two days longer than heifer calves.
Calving date = breeding date + breed gestation length
| Breed | Average gestation |
|---|---|
| Holstein, Jersey | 279 days |
| Angus | 281 days |
| Hereford | 285 days |
| Simmental, Charolais | 289 days |
| Brahman | 292 days |
The normal window shown is about 9 days either side of the average. Breed associations publish gestation charts for their breeds, and the sire's EPD for gestation length can shift the date further.
AI date or bull turnout date?
With artificial insemination you have an exact date, so the calculator gives a precise due date. With natural service, enter the day the bull went in with the cows. That gives the earliest likely calving date. Cows that did not settle on their first heat will calve about 21 days later for each missed cycle, so a 60-day breeding season means calves arriving over roughly 60 days.
When to rebreed for a calf every year
A year is 365 days and a cow is pregnant for about 283 of them, which leaves about 82 days between calving and getting her bred again. The calculator shows that rebreed by date. First-calf heifers take longer to start cycling after calving, which is why many producers breed heifers a few weeks ahead of the main herd.
Rebreed by = calving date + (365 − 283) = calving date + 82 days
Planning a whole herd? The printable cow gestation chart lists the calving date for every breeding date of the year. Also breeding goats or sheep? See the goat and sheep calculators.
How many months is a cow pregnant?
About 9 months and 10 days. The average is 283 days, ranging from 279 days for Holsteins to about 292 for Brahman cattle.
Frequently asked questions
How many days is a cow pregnant?
About 283 days on average, ranging from 279 days for Holsteins to about 292 for Brahman.
How soon can I tell if a cow is pregnant?
Ultrasound from about 28 to 35 days after breeding, palpation from about 35 to 45 days, and blood tests from about 28 days.
When should a cow be bred back after calving?
Most producers aim to rebreed within 80 to 85 days of calving to keep a 365-day calving interval.
Sources
- Montana State University Extension: Beef gestation table (PDF)
- Kansas State University Beef Tips: Gestation length in modern beef cattle
Reference charts
More gestation calculators
Horse Gestation Calculator
Foaling date with the 320 to 370 day window.
Goat Gestation Calculator
Kidding date for dairy, meat and pygmy goats.
Sheep Gestation Calculator
Lambing date for ewes, with the normal window.
Dog Pregnancy Calculator
Whelping date with week-by-week milestones.
Cat Pregnancy Calculator
Kitten due date and stages of cat pregnancy.
Rabbit Gestation Calculator
Kindling date and nest box date.