How do I calculate my cat's due date?

Enter the first mating date into our calculator. If multiple matings occurred, add additional dates — the calculator averages them for a more accurate estimate. Key milestones include ultrasound confirmation at day 21, fetal development at day 28, and queening box preparation at day 55.

What are the signs of cat pregnancy?

Early signs of cat pregnancy include: pink, enlarged nipples ("pinking up") at around week 3 — this is the most reliable early indicator; increased appetite and possible morning sickness at weeks 3-4; noticeable weight gain and abdominal enlargement by weeks 4-5; and nesting behavior (seeking quiet, dark spaces) starting around week 7. Unlike dogs, cats are induced ovulators — ovulation occurs after mating, not on a regular cycle — so the mating date is typically an accurate conception marker. If you suspect pregnancy, a vet can confirm it via ultrasound as early as day 21.

How long is the cat gestation period compared to dogs?

Cat gestation averages 65 days (range 61-67 days), compared to dogs at 63 days (range 58-68 days). While the averages are similar, cats have a tighter range — 6 days vs. 10 days for dogs. Cat litters average 4-6 kittens, compared to dogs which vary greatly by breed (1-12+ puppies). Cat pregnancies are less variable because cats are induced ovulators, making the conception date easier to pinpoint. Both species share similar pregnancy confirmation milestones: ultrasound at ~day 21-28 and X-ray at ~day 45.

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Cat Gestation Calculator

Calculate your cat's due date, track key developmental milestones, and prepare for queening.

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主要な知識

How Long Are Cats Pregnant?

Cats are pregnant for 65 days (range: 63-67 days) from ovulation — about 9 weeks and 2 days, slightly longer than dogs. Cats are induced ovulators, meaning mating triggers egg release, so the mating date is usually a reliable conception date marker.

Source: AAFP Feline Reproduction Guidelines

Feline Gestation Timeline

Day 1-14: Implantation. Day 21-28: Ultrasound confirms pregnancy. Day 30-35: Nipples pink and enlarge ("pinking up"). Day 45-50: X-ray shows skeletons. Day 63-67: Delivery. Nesting behavior begins around day 55. Provide a quiet, warm nesting box by day 55.

Source: AAFP Feline Reproduction Guidelines

Signs of Cat Pregnancy

Week 3: Pink, enlarged nipples ("pinking up") — the most reliable early sign. Week 4-5: Weight gain and possible morning sickness. Week 6-7: Noticeable abdominal enlargement. Week 8: Visible kitten movement, nesting behavior. If you suspect pregnancy, confirm with a vet by day 21-28 via ultrasound.

Source: ISFM Feline Reproduction Guide

Cat Pregnancy Stages

First trimester (days 1-21): Embryonic development, no visible signs. Second trimester (days 22-42): "Pinking up" at day 30-35. Third trimester (days 43-67): Rapid growth, nesting from day 55. Milk production possible from day 60. Average litter size: 4-6 kittens.

Source: AAFP / ISFM Feline Guidelines

petsMetricsが査読付き獣医ソースを使用して検証したデータ。引用：ASPCA、AVMA、AAFP。最終レビュー：2026。

The Science Behind the Cat Gestation Calculator

Feline gestation is 65 days from ovulation (range: 63-67 days), as documented in AAFP and ISFM reproduction guidelines. Since cats are induced ovulators (ovulation triggered by mating), the mating date is a reliable marker. Our calculator uses mating date + 65 days for the most likely due date, with a ±2-day range. Key milestones — ultrasound at day 21-28, X-ray at day 45-50, nesting box preparation at day 55 — are aligned with AAFP clinical recommendations.

References: AAFP Feline Reproduction Guidelines; ISFM Guidelines on Feline Reproduction— via petsMetrics

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