Free Cat Pregnancy Due Date calculator with clear step-by-step results.
Feline gestation averages about 65 days from mating, with normal queening falling between days 63 and 67. Adding the gestation length to the mating date gives the expected date, and the window either side is what tells you whether labour is early, on time or overdue.
Due date
Due date = mating date + gestation days (65 by default)
Normal window
Normal delivery spans mating date + 63 to mating date + 67 days
An estimate based on average feline gestation. Ultrasound or radiographic staging by a veterinarian is far more reliable, and any sign of difficult labour is an emergency.
Cats can mate repeatedly across an oestrus. Use the first mating for the earliest possible date and the last for the latest, and treat the span as the queening window.
Delivery before day 60 risks non-viable kittens, and going beyond day 70, or straining for more than 30 minutes without producing a kitten, warrants immediate veterinary attention.