How long is a cow pregnant?

About 283 days on average, or a little over nine months. Most beef cows calve between 279 and 292 days after breeding, depending on breed and the sex of the calf.

How long is a goat pregnant?

About 150 days, with most does kidding between 145 and 155 days after breeding. Smaller breeds such as Pygmy and Nigerian Dwarf often kid a few days earlier.

How long is a ewe pregnant?

About 147 days, with most ewes lambing between 142 and 152 days. Ewes carrying twins or triplets often lamb a day or two early.

When will my first calves come if the bull went in on a date?

Add the short end of the range to the bull-in date: 279 days for cattle. Cows that settle on the first day can calve that early, so be ready from then.

How long should the bull stay in?

Many operations aim for 60 to 90 days, which gives each cow about three to four heat cycles of 21 days to settle. The calculator shows how many cycles your dates allow.

Gestation and due date calculator

Put in the day she was bred, or the day the bull went in and the day he came out, and get the due date and the window the births will fall in. For cattle, sheep, goats, hogs and horses.

Works for cattle, sheep & goats, hogs and horses. Free, no account, and nothing you type leaves your phone.

Bred on

Using 283 days for cattle, with a normal range of 279 to 292.

Pick a date.

See a mistake, or a number that doesn't look right?

How this is calculated

The formulas

Due date: breeding date + average gestation
The middle of the window, not a promise.
Normal window: breeding date + shortest normal … + longest normal
Season, male in and out: first: in date + shortest · bulk: in + average to out + average · last: out date + longest
A female bred on the first day can deliver as early as the short end; one bred on the last day as late as the long end.
Heat cycles covered: days the male is out ÷ cycle length
21 days for cattle, goats, hogs and horses; 17 for sheep.

Where the defaults come from, and the limits

Cattle: 283 days (279–292). 283 days is the usual beef-cow average. Most British breeds run a day or two shorter, Continental and Brahman-influenced cattle a few days longer, and bull calves are carried about a day longer than heifers.
Sheep: 147 days (142–152). 147 days is the usual average. Fast-maturing meat breeds tend to the short end, fine-wool breeds to the long end, and twins and triplets often come a day or two early.
Goats: 150 days (145–155). 150 days is the usual average for meat and dairy goats. Pygmy and Nigerian Dwarf does often kid a few days earlier.
Hogs: 114 days (112–116). 114 days — the old "three months, three weeks and three days". Sows are among the most consistent; most farrow within a day or two of it.
Horses: 340 days (320–370). 340 days is the usual average, but mares vary more than any other species here: anywhere from about 320 to 370 days is normal, and mares bred early in the year often carry longer.
The averages are the ones published in university extension and breed-association guidance. A herd's own records beat any average: if your cows run long every year, trust that.

Questions people ask

How long is a cow pregnant?: About 283 days on average, or a little over nine months. Most beef cows calve between 279 and 292 days after breeding, depending on breed and the sex of the calf.
How long is a goat pregnant?: About 150 days, with most does kidding between 145 and 155 days after breeding. Smaller breeds such as Pygmy and Nigerian Dwarf often kid a few days earlier.
How long is a ewe pregnant?: About 147 days, with most ewes lambing between 142 and 152 days. Ewes carrying twins or triplets often lamb a day or two early.
When will my first calves come if the bull went in on a date?: Add the short end of the range to the bull-in date: 279 days for cattle. Cows that settle on the first day can calve that early, so be ready from then.
How long should the bull stay in?: Many operations aim for 60 to 90 days, which gives each cow about three to four heat cycles of 21 days to settle. The calculator shows how many cycles your dates allow.

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