How long is a cow pregnant?
Gestation in cattle averages about 283 days — a little over nine months — counted from breeding or artificial insemination. The calculator adds 283 days for the estimated calving date and shows a window from day 274 to day 292, because individual cows and breeds vary.
Estimated calving date = breeding or AI date + 283 days
Breed makes a noticeable difference: many dairy breeds tend to calve a few days earlier than the average, while Bos indicus breeds such as Brahman, and some continental beef breeds, often carry a little longer. Bull calves and twins also affect gestation length — twins tend to come early. If you know your herd’s typical gestation, add or subtract the difference from the estimate.
Key dates for a pregnant cow
| Day after breeding | Typical event |
|---|---|
| About 28–35+ | Pregnancy can usually be confirmed by ultrasound (early) or rectal palpation (from about 35 days) |
| About 223 | Common dry-off date for dairy cows (about 60 days before calving) |
| 274 | Start of the calving window — move to the calving area and watch closely |
| 283 | Estimated calving date |
| 292 | End of the typical window — consult your vet if she has not calved |
To find any of these dates for your cow, enter her breeding date above and use the Add Days to Date calculator for the day numbers in the table.
Signs that calving is close
In the last weeks the udder fills (“bagging up”), the vulva swells and relaxes, and the ligaments around the tail head soften. Restlessness, separating from the herd and a full, tight udder usually mean calving is near. Agree with your vet when to call for help, for example if strong labour does not produce progress within a reasonable time. For dogs and cats, see the Dog Pregnancy Calculator and Cat Pregnancy Calculator.