How Long Are Cows Pregnant? Cattle Gestation by Breed

By the HerdMath team · Updated 2026-09-18

A cow is pregnant for about 283 days, just over 9 months. It varies by breed: Holsteins and Jerseys average about 279 days, Angus about 281, and Brahman-influenced cattle up to about 292.

Cattle Gestation Calculator
Breed-adjusted calving date, heat checks and dry-off.
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Cattle gestation by breed

BreedAverage gestation
Holstein, Jerseyabout 279 days
Angusabout 281 days
Shorthornabout 282 days
Herefordabout 285 days
Simmental, Charolais, Limousinabout 289 days
Brown Swissabout 290 days
Brahmanabout 292 days

What changes the length

  • Breed of the sire and dam: the biggest factor. For crossbred calves, the sire's breed has a strong effect.
  • Calf sex: bull calves are often carried a day or two longer than heifers.
  • Twins: usually born earlier.
  • Heifers vs cows: first-calf heifers often calve slightly earlier.

Planning a calving season

To calve in a set window, count back about 283 days from when you want calves to arrive. Turn the bull in then, and leave him in for 60–90 days, which covers three or four heat cycles. Pull him and the calving season stays tight. The calculator gives the full window when you enter bull-in and bull-out dates.

Cattle Gestation Calculator
Breed-adjusted calving date, heat checks and dry-off.
Open the calculator

Common questions

How many months is a cow pregnant?

About 9 months and 10 days (roughly 283 days).

How early can a cow calve safely?

Calves born more than about 2 weeks early are often weaker and need close watching. Very early calving can be a sign of disease; talk to your vet.

Figures are typical values from university extension and breed-association guidance. Estimates only. Individual animals vary — confirm pregnancy and health questions with your veterinarian.