Cow Gestation Calculator
Knowing when your cows will calve helps you prepare facilities, schedule veterinary checks, and plan your calving season. Select the breeding date and cattle breed to calculate the expected calving date and calving window.
Cattle gestation averages about 283 days (roughly 9 months and 10 days), but it varies by breed. Dairy breeds like Holstein and Jersey tend toward shorter gestations (279 days), while larger beef breeds like Charolais and Simmental run longer (287 days). Brahman cattle have the longest average gestation at about 292 days.
Here are the average gestation lengths by breed:
- Holstein: 279 days
- Jersey: 279 days
- Angus: 281 days
- Shorthorn: 282 days
- Hereford: 285 days
- Limousin: 285 days
- Charolais: 287 days
- Simmental: 287 days
- Brahman: 292 days
The calving window shown (plus or minus 4 days) covers the range where most cows will calve, but individual variation can be wider. Factors that influence actual calving date include the calf's sex (bull calves tend to gestate 1-2 days longer), the cow's age (heifers may calve slightly earlier), nutrition, and environmental stress.
For best results, record the exact breeding date when using AI (artificial insemination) or note when a bull was with the cow. With natural service in a bull-breeding pasture, the breeding date is an estimate unless observed directly.