How to Calculate Your Dog's Due Date

Method 1: count 63 days from mating

The simplest method: add 63 days to the mating date. If she was mated on 1 March, the due date is 3 May. Because mating can precede ovulation by a day or two, treat the answer as the middle of a 58–68 day window rather than a single day. Our dog due date calculator does this instantly and shows the full window.

Method 2: count 63 days from ovulation

Breeders who progesterone-test know the ovulation date, and 63 days from ovulation is the most accurate count available. Ovulation is confirmed by a progesterone level around 5 ng/ml (LH surge +2 days). This method removes the 1–2 day mating uncertainty entirely.

What if there were two matings?

Enter both dates and average them. Puppies in one litter can be conceived on different days (and even have different fathers), so the average of the mating dates is the most sensible single estimate. The calculator above does the averaging for you.

A worked example

Mated on 10 October and 12 October. Average = 11 October. Due date = 11 October + 63 days = 13 December. Safe window: 8 December (day 58) to 18 December (day 68). Set up the whelping box by 6 December (day 56).

Try the calculator

Guides explain the rules; the tool does the maths. Dog Due Date Calculator gives you an instant, personalised answer.

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