Dog pregnancy timeline and due date calculator
Dog pregnancy timeline and due date planning
This calculator estimates a dog’s pregnancy timeline from a mating date, an assumed ovulation offset, and a mild breed-size adjustment. It outputs an estimated due date, a practical due window, current pregnancy day (based on your reference date), and a milestone table you can export.
How the calculator estimates the due date
The timeline is anchored on an assumed ovulation date. You provide a mating date and an ovulation offset (in days) to approximate ovulation timing.
Assumed ovulation date is calculated as:
\( D_{ovulation} = D_{mating} + \Delta_{ovulation} \)
Estimated due date uses a typical gestation length with a small adjustment by breed size:
\( D_{due} = D_{ovulation} + G \)
Where \(G\) is the estimated gestation length in days. The calculator also provides a narrow planning window around the estimate:
\[ D_{window\_start} = D_{due} - 2,\quad D_{window\_end} = D_{due} + 2 \]
Current pregnancy day and progress
Your Reference date controls the “today status” and progress calculation:
\( Day = D_{reference} - D_{ovulation} \)
Progress is computed as:
\( Progress\% = \frac{Day}{G} \times 100 \)
If your reference date is before the assumed ovulation date, progress is shown as 0 until the timeline starts.
Milestones table for planning
The milestones table provides practical checkpoints that many owners and breeders plan around, such as confirmation windows, preparation time, and the due window. Use Detail level to switch between a simplified milestone list and a more detailed planning view. The table remains visible in both modes and supports column reordering, hiding, and export.
Important limitations and safety note
This tool provides planning estimates only. Individual dogs can vary, and precise timing depends on ovulation confirmation and veterinary assessment. If your dog shows distress, unusual discharge, prolonged labor signs, or the pregnancy extends beyond the displayed due window end, contact a veterinarian promptly.