Cat Pregnancy Calculator — Feline Gestation Due Date
Track your cat's pregnancy week by week. Enter the number of days since mating to see how many days remain until the average due date (day 65), which gestation stage she is in, and upcoming developmental milestones.
days
Average feline gestation is 65 days (range 63–67 days)
- 1
Average feline gestation
65Normal range is 63–67 days. - 2
Days since mating
14 - 3
Days remaining
65 − 14 = 51
How does this calculator work?
Cat pregnancy lasts an average of 65 days (63–67 day range). Subtract elapsed days since mating from 65 for the days remaining. Key milestones: nipple pinkening at day 21, ultrasound confirmation by day 28, X-ray litter count from day 45, nesting starts around day 56.
Formula
How this is calculated
Cat (queen) gestation averages 65 days from mating, with a normal range of 63–67 days. First-time mothers or cats carrying small litters sometimes go closer to 67 days; large litters may arrive a day or two earlier. Birth before day 61 is considered premature, and kittens born before day 58 rarely survive without intensive veterinary care.
Feline pregnancy is conventionally divided into thirds. The first third (days 1–21) covers fertilisation and embryo implantation; the second third (days 22–42) is the period of most active organ development; and the final third (days 43–65) is mainly growth and preparation for birth. Around day 21, the nipples begin to turn pink and enlarge — a visible sign known as "pinking up". By day 45, the kittens' skeletons are calcified enough to appear on X-ray, allowing the vet to count the litter size.
This calculator uses days since mating as input rather than a calendar date picker for simplicity and locale independence. If you know the exact mating date, subtract today's date to find the elapsed days. Some cats have multiple matings over 2–4 days; use the first confirmed mating as day 0 for the earliest possible due-date estimate.
Frequently asked questions
Feline gestation averages 65 days (about 9 weeks), with a normal range of 63–67 days. Births outside this window may need veterinary attention — consult your vet if your cat has not given birth by day 67 or shows distress.
A vet can confirm pregnancy by palpating the abdomen around day 25–35, ultrasound from about day 18–20 (heartbeats visible around day 21–24), or X-ray from day 45 onward when the kittens' bones are calcified. 'Pinking up' of the nipples around day 21 is a visible home indicator but not definitive on its own.
Normal birth can occur between days 63 and 67. If day 67 passes with no labour, or if the cat shows signs of distress (straining without producing kittens, bloody discharge, lethargy), contact your vet immediately. A retained kitten or uterine inertia can be life-threatening.
TG we-Calculate Editorial Team. (2026). Cat Pregnancy Calculator — Feline Gestation Due Date [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/cat-pregnancy-calculator
TG we-Calculate Editorial Team. "Cat Pregnancy Calculator — Feline Gestation Due Date." TG we-Calculate. 2026. https://we-calculate.com/calculator/cat-pregnancy-calculator.
TG we-Calculate Editorial Team, "Cat Pregnancy Calculator — Feline Gestation Due Date," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/cat-pregnancy-calculator
@misc{wecalculate_cat_pregnancy_calculator, title = {Cat Pregnancy Calculator — Feline Gestation Due Date}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/cat-pregnancy-calculator}}, year = {2026}, note = {TG we-Calculate} }
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