How this calculator works
Domestic rabbits use a central 31-day estimate and a broad 28 to 35 day range. The FAO husbandry guide supports preparing the nest a few days before kindling; the reminder here is three days before the estimate. Pregnancy assessment belongs to an experienced veterinarian, not untrained abdominal palpation. For another species, supply a documented gestation and range. Date arithmetic uses whole calendar days in UTC, so daylight-saving changes do not shift the result. A negative elapsed value means the reference date is still ahead; a negative remaining value means the estimate has passed.
Formula
Due date = reference date + assumed gestation days. Reverse mode subtracts the same duration. The default is 31 days, with a 28 to 35 day planning window. Days remaining = due date - observation date. The window is not a guarantee.
Worked example
A domestic rabbit bred on 1 January 2026 has an estimated kindling date of 1 February and a nest-box reminder on 29 January. On 15 January, 17 days remain to the central estimate.
Advertisement
Frequently asked questions
Does the estimated date confirm pregnancy?
No. A recorded mating may not result in pregnancy. Veterinary examination and appropriate imaging are needed for confirmation.
Can I work backwards from a due date?
Yes. Choose breeding-date mode. The answer is the date implied by the assumed duration, not proof of the actual conception day.
Why might birth occur outside the window?
Breeding and ovulation dates can differ, and litter size, breed and individual history influence timing. Arrange monitoring with your veterinarian instead of using the window as a safety test.