Animal Gestation Calculator

Cow Gestation Calculator

A cow's gestation period is about 283 days, or roughly 9 months and 1 week, though it ranges from 279 to 292 days depending on breed and individual animal.

How to use the cow gestation calculator

  1. 1. Choose what you know. Enter the breeding date to get a due date, or switch to the target due date mode to work backwards to the breeding date you need.
  2. 2. Refine the inputs. Pick the breed so the calculator uses the right average gestation length.
  3. 3. Plan around the range. Use the earliest and latest dates and the milestone timeline to schedule checks, feed changes and preparation of the calving area.

Calculate a calf due date

What do you know?

Bull calves are typically carried slightly longer than heifer calves.

Estimated calving date

Tuesday, 22 June 2027

Earliest

18 Jun 2027

Latest

1 Jul 2027

283 days remaining0% complete

0 of 283 days elapsed

Milestone timeline

Key Cow pregnancy milestones with calculated calendar dates
DayMilestoneDate
30Pregnancy check by ultrasound12 Oct 2026
223Dry off (60 days pre-calving)23 Apr 2027
253Pre-calving vaccinations23 May 2027
273Move to calving pen12 Jun 2027
283Expected calving22 Jun 2027

What to do next

How long is a cow's gestation period?

The average is 283 days from breeding to calving, about 9 months and 1 week. Anything between 279 and 292 days is normal, and a typical litter is 1 calf. Treat the calculated date as the middle of that window rather than a fixed appointment.

Cow gestation table: breeding date to calving date

Breeding dates one week apart with the matching calving date at 283 days.

Twelve sample Cow breeding dates and their calculated due dates
Breeding dateExpected calving date
12 Sept 202622 Jun 2027
19 Sept 202629 Jun 2027
26 Sept 20266 Jul 2027
3 Oct 202613 Jul 2027
10 Oct 202620 Jul 2027
17 Oct 202627 Jul 2027
24 Oct 20263 Aug 2027
31 Oct 202610 Aug 2027
7 Nov 202617 Aug 2027
14 Nov 202624 Aug 2027
21 Nov 202631 Aug 2027
28 Nov 20267 Sept 2027

How breed changes the calving date

Selecting a breed swaps the average the calculator uses, which can move the calving date by more than a week.

Cow breeds and their average gestation length in days
BreedAverage daysDifference
Average283—
Holstein279-4 days
Jersey279-4 days
Angus281-2 days
Hereford285+2 days
Simmental287+4 days
Charolais287+4 days
Brown Swiss290+7 days
Brahman292+9 days

Working backwards from a target calving date

If you want calfs on the ground in a particular week, switch the calculator to target date mode and enter the date you are aiming for. It subtracts 283 days to give the breeding date to book, plus the earliest and latest service dates that still land inside your window.

Cow gestation calculator FAQs

How long is a cow pregnant?

A cow is pregnant for about 283 days, which is roughly nine months and one week. Normal gestation runs from 279 to 292 days depending on breed, calf sex and whether she is carrying twins.

Which cattle breeds have the shortest gestation?

Dairy breeds are shortest. Holstein and Jersey cows average 279 days, Angus about 281 days. Continental beef breeds such as Simmental and Charolais average 287 days, and Brahman cattle average 292 days.

Does calf sex change the due date?

Slightly. Bull calves are typically carried about one to two days longer than heifer calves, so a herd average of 283 days becomes roughly 284 days for a bull calf and 282 days for a heifer calf.

When should a cow be dried off?

Dairy cows are normally dried off 60 days before the expected calving date, which is around day 223 of gestation. A shorter dry period reduces milk yield in the following lactation.

How early can pregnancy be confirmed in cattle?

Transrectal ultrasound detects pregnancy from about day 28, blood tests from about day 28, and manual palpation from about day 35. Confirming again at 60 to 90 days catches early embryonic loss.

How accurate is a cow gestation calculator?

It gives a planning estimate from breed averages. Around two thirds of cows calve within about five days of the calculated date, but the full normal range spans nearly two weeks, so prepare the calving area early.

More gestation pages

Livestock gestation chart