Cow Gestation Calculator: How Long Is a Cow Pregnant?

By Hassan Nawaz, Publisher. Updated November 11, 2026.

Enter the breeding date to get the expected calving date, the normal range, and how far along your cow is today.

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Expected calving date
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Earliest normal
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Latest normal
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Rebreed by (calf every 12 months)
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Today

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

BredDue, day 283Normal window: 274 to 292 daysPreg checkDry offCalving pen
Typical cow pregnancy from breeding to calving, using the 283 day average. The shaded part is the normal calving window.
BreedAverage gestation
Holstein, Jersey279 days
Angus281 days
Hereford285 days
Simmental, Charolais289 days
Brahman292 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.

Signs of calving. Udder fills (bagging up), the tailhead ligaments relax, the vulva swells and the cow separates from the herd. Call your vet if active labor goes past 2 hours without progress, or if a heifer pushes for more than 1 hour.

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.

Sample calving dates

BredCalving (day 283)Earliest (day 274)Latest (day 292)
Jan 15, 2026Oct 25, 2026Oct 16, 2026Nov 3, 2026
Mar 15, 2026Dec 23, 2026Dec 14, 2026Jan 1, 2027
May 15, 2026Feb 22, 2027Feb 13, 2027Mar 3, 2027
Jul 15, 2026Apr 24, 2027Apr 15, 2027May 3, 2027
Sep 15, 2026Jun 25, 2027Jun 16, 2027Jul 4, 2027
Nov 15, 2026Aug 25, 2027Aug 16, 2027Sep 3, 2027

The full list is in the cow gestation chart. To plan the breeding season, see the calving season guide. For comparison with other animals, see the animal gestation periods chart.

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.

What is the gestation period for a cow?

About 283 days, a little over nine months. Breed changes it: 279 days for Holstein and Jersey, 281 for Angus, 285 for Hereford, 289 for Simmental and Charolais and 292 for Brahman.

How do I calculate a cow's due date?

Add the breed's gestation length to the breeding or AI date. A cow bred on Jun 1 with a 283 day gestation is due about Mar 11 the next year.

Sources

Reference charts

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Last updated November 11, 2026. Results are estimates for planning. See how we build and check our tools in our editorial policy. Found an error? Tell us.