Cat Pregnancy Calculator (Due Date & Week-by-Week)
Estimate a cat’s due date from the mating date (or a vet estimate), then see a simple week-by-week timeline.
Quick answer
Typical cat gestation
Many cats carry kittens for about 63 days on average, with a common range around 58–67 days. This calculator shows a due date plus a realistic window.
If you’re concerned about your cat’s health, contact a veterinarian.
Inputs
Mating date (or “today” for vet estimate mode).
Example: vet says “about 4 weeks” → 28 days.
Gestation length
Default is 63 days. You can adjust it to match your vet’s guidance.
When to call a vet
- Straining with no kittens, severe pain, collapse, or heavy bleeding.
- Green/black discharge before the first kitten is born.
- More than 2 hours of strong contractions with no kitten delivered.
- Cat seems very ill, won’t eat, or has a fever.
How this calculator works (formulas)
Due date
DueDate = StartDate + GestationDays
Due date window
We show a practical window: (DueDate − 5 days) to (DueDate + 4 days).
Week-by-week
WeekNumber = floor(DaysPregnant ÷ 7) + 1
This is a simple week grouping for readability. Real milestones vary by cat and litter.
FAQ
How long are cats pregnant?
Many cats carry kittens for around 63 days, with variation between individuals. This calculator lets you adjust gestation length.
What if I don’t know the exact mating date?
Use the “vet estimate” option and enter how many days pregnant your vet believes your cat is. The calculator will work backward to estimate the start date.
How accurate is a due date calculator?
It’s an estimate. Ovulation timing, litter size, and individual variation can shift the true due date. Always watch for signs of labor and contact a veterinarian if you’re concerned.