Cat Pregnancy Calculator
Due date, kittening window, and vet checks from mating date for queens.
What it does
Cat pregnancy averages 65 days from mating, a touch longer than the canine 63. Queens ovulate after the act itself, so breeding dates predict better in cats than in dogs, though individual timing still spreads the window.
The tool above takes the mating date. It returns the 65 day due date with the 60 to 70 day window and the day 25 ultrasound point beside them.
The default mating of October 1 2026 gives December 5 due, window November 30 to December 10, ultrasound from October 26. Breedings near January 1 land near March 7 with the same 65 day step.
Lengths follow veterinary charity whelping guidance with the veterinary manual reproduction chapters matching them. Both name about 63 to 65 days with 60 to 70 possible from first breeding.
How to use
- Enter the first mating date.
- Read the due date for the 65 day mark.
- Plan around the full window, not the single day.
- Book ultrasound from day 25 and x-ray past day 45.
- Watch nesting and appetite near the window.
Formula
- 65
- Average days from mating to birth in queens.
- 60-70
- Breeding date window covering timing spread.
- 25 / 45
- Ultrasound and x-ray timing in days.
All dates compute in UTC so zones never shift a day. Past day 70 without labor signs needs a vet visit; single kitten litters often run long.
Worked example
Example: mated October 1 2026
Mating date 2026-10-01.
- Due: Oct 1 + 65 days = Dec 5 2026.
- Early: Oct 1 + 60 = Nov 30.
- Late: Oct 1 + 70 = Dec 10.
- Ultrasound: Oct 1 + 25 = Oct 26.
- Tool shows Sat Dec 05 2026, window, Oct 26 ultrasound.
Reference table
| Day | Check | Method |
|---|---|---|
| 21 | Palpation possible | Vet exam |
| 25 | Ultrasound reliable | Heartbeat check |
| 45+ | Skeleton on x-ray | Count estimate |
| 60-70 | Kittening window | Watch closely |
Limits
- Mating dates predict well but never exactly.
- Breed and litter size shift real lengths.
- Single kitten litters often run long.
- Vet imaging beats every calendar estimate.
Common mistakes
- Treating the due date as exact from mating.
- Skipping confirmation imaging entirely.
- X-raying too early for skeletons or counts.
- Missing nesting and restlessness before labor.
- Planning travel inside the window.
Try it yourself
Quick checks. Answers sit tucked under each question.
Mated Jan 1: due and window?
Due Sat Mar 07 (65 d), window Mar 02 to Mar 12, ultrasound Jan 26.
Ultrasound for Oct 1 mating?
Oct 1 + 25 = Oct 26.
Past day 70 with no labor?
See the vet promptly to rule out complications.
Questions
How long are cats pregnant?
About 65 days from mating; 60 to 70 days covers the normal window.
When can pregnancy be confirmed?
Palpation from day 21, ultrasound from day 25, x-ray counts past day 45.
How do I know labor is near?
Nesting, restlessness, and appetite drop, usually within a day.
Cats versus dogs?
Queens average 65 days against bitches at 63, with tighter mating based timing.
Single kitten different?
Often longer with weaker labor signals; vet monitoring matters more.
Spay while pregnant?
Discuss timing and risks with your vet promptly; options narrow fast.