Cow Gestation Calculator: Due Date and Milestones
Cow Pregnancy Calculator
This calculator helps you estimate a cow’s expected calving due date based on a breeding date and a chosen gestation length. It also generates a practical milestone timeline and a clear progress visualization to support planning and herd management.
How the due date is calculated
The expected calving date is computed by adding the gestation length (in days) to the breeding date:
\[\text{DueDate} = \text{BreedingDate} + \text{GestationDays}\]
Important: the result is an estimate. Actual calving can occur earlier or later due to natural variation.
Progress and remaining time
Progress is computed relative to a Reference date (by default, today). First, we compute elapsed time in days:
\[\text{ElapsedDays} = \text{ReferenceDate} - \text{BreedingDate}\]
Then remaining days until the due date:
\[\text{RemainingDays} = \text{GestationDays} - \text{ElapsedDays}\]
Finally, progress percentage (bounded to 0–100):
\[\text{Progress\%} = \frac{\text{ElapsedDays}}{\text{GestationDays}} \times 100\]
Milestone timeline table
The table provides common planning points across early, mid, and late gestation. Each milestone row includes the target date, status (Passed/Today/Upcoming), and a highlight rule based on your chosen alert window.
Dairy vs Beef: the calculator adjusts the milestone list slightly. For example, dry-off planning is typically more relevant for dairy herds, while beef management may focus on observation and facility readiness near term.
How to use this calculator effectively
- Enter the breeding date as accurately as possible.
- Keep the gestation length at the default if you want a standard estimate, or adjust it if you have strong farm or breed-specific data.
- Set the reference date if you want to evaluate progress for a date other than today (planning ahead or reviewing the past).
- Use the alert window to highlight milestones that are coming soon.
Practical note
This tool is informational only. If you observe signs of imminent calving, health issues, or unusual behavior, consult a qualified veterinarian or experienced livestock professional.