Cat Pregnancy Calculator
Enter the mating date to find your cat's estimated due date, days remaining and current pregnancy stage.
Average cat gestation is 65 days (range 63–67 days).
Mating date
How Long Is Cat Pregnancy and How Is It Calculated?
Cat pregnancy is remarkably short compared to human pregnancy. Knowing the due date is critical for timing veterinary appointments, adjusting nutrition and making pre-birth preparations.
Average Cat Gestation Period
Cat gestation varies slightly by breed, but the reference values for all domestic cat breeds are:
| Scenario | Duration |
|---|---|
| Minimum (premature threshold) | 58 days |
| Normal lower limit | 63 days |
| Average (used by calculator) | 65 days |
| Normal upper limit | 67 days |
| Prolonged (vet required) | 70+ days |
How the Due Date Calculation Works
The calculator adds 65 days to the mating date to find the average due date, and also displays the 63–67 day normal range. If the exact mating day is unknown, enter the first observed mating date — this usually introduces an error margin of one to two days.
| Stage | Days | Development | Signs |
|---|---|---|---|
| 1st Trimester | Days 1–21 | Embryo formation and implantation | Not externally visible; possible morning sickness |
| 2nd Trimester | Days 22–42 | Organ and skeletal development | Belly growth, movement felt, increased appetite |
| 3rd Trimester | Days 43–65 | Rapid weight gain | Visible belly, breast swelling, nesting behaviour |
What Are the Signs of Cat Pregnancy?
The first few weeks may show no definitive signs. As pregnancy progresses, however, both physical and behavioural changes become increasingly apparent.
Physical Changes (Nipples and Weight Gain)
Behavioural Changes (Nesting Instinct)
Nesting Instinct
One to two weeks before birth the cat seeks quiet, dark and enclosed spots. She gathers blankets, towels or clothing. This behaviour signals it is time to prepare a birthing box.
Increased Affection
Some cats demand more contact during pregnancy — climbing onto laps, vocalising more. This is linked to hormonal changes.
Withdrawal / Hiding
Other cats become more introverted and prefer solitude. Both behaviours are normal.
Increased Appetite
Appetite noticeably increases from the 2nd trimester onward. In the final 3 weeks calorie requirements can rise by 25–50%.