Calving planning tool
Cow gestation and calving date calculator
Work out when calves are due from a breeding date, the calving window from a breeding season, or when to turn bulls out to start calving on the date you want.
A beef cow is pregnant for about 283 days. To get the calving date, add 283 days to the breeding date: a cow bred on May 15 is due about February 22. Brahman and other Bos indicus cattle carry calves longer, around 290 days or more. To start calving on a set date, count the gestation length back to find the bull turnout date.
Example dates. Change them to your own.
Most calves arrive between Fri, Feb 12, 2027 – Thu, Mar 4, 2027.
Watch · 44 sec
The 283-day rule: when to turn out bulls
Average cattle gestation is about 283 days. Count back from the calving date you want to find your bull turnout date.
Read the transcript
The 283-day rule. Average cattle gestation is about 283 days; Brahman-influenced cattle often carry about a week longer, so know your breed. Pick your calving date and count back 283 days. For first calves on Feb 1, 2027, turn bulls out by Apr 24, 2026. Turnout cheat sheet: calves wanted by Jan 15, 2027, bulls in by Apr 7, 2026; Feb 1, 2027, Apr 24, 2026; Feb 15, 2027, May 8, 2026; Mar 15, 2027, Jun 5, 2026. Bonus: 60 days with the bulls is about 60 days of calving. A tight breeding season gives you a tight, even calf crop.
Planning tips
- Calve before grass, not in the worst weather. Match the calving season to your forage and your labor. Many herds aim to calve 30 to 60 days before green-up.
- Keep the season tight. Three 21-day cycles (63 days) gives every cow three chances and a uniform calf crop.
- Breed heifers early. Start heifers two to three weeks ahead of the cows so they calve first and have more time to rebreed.
- Know your bulls. Gestation length EPDs and breed both shift the date. Use a custom length if your calves run early or late.
How long is a cow pregnant?
About 283 days, or a little over nine months, for most beef cows. Bos indicus cattle such as Brahman carry calves longer, often around 290 days or more, and crossbreds with Brahman fall in between. Bull calves are usually carried a day or two longer than heifer calves.
How do I calculate a calving date from a breeding date?
Add the gestation length to the breeding date. With 283 days, a cow bred on May 15 is due about February 22 the next year. Most calves arrive within about 10 days either side of that date.
When should I turn the bulls out to start calving on a set date?
Count the gestation length back from the first calving date you want. To start calving on February 20 with 283-day gestation, turn bulls out about May 13. Heifers are often bred two to three weeks earlier than the cows so first-calvers have more time to recover before rebreeding.
How long should a breeding season be?
Many cow-calf operations aim for a 60 to 90 day breeding season. Each 21-day heat cycle the bulls stay out gives each open cow another chance to conceive. A shorter season gives a tighter, more uniform calf crop and makes calving easier to manage.
Does the bull affect gestation length?
Yes. Breed and sire both matter. Some breed associations publish a gestation length EPD, and a bull with a lower gestation length EPD tends to sire calves born a few days earlier. Use a custom gestation length here if you know your bull or breed runs longer or shorter.