Cat Pregnancy Calculator
Estimate a cat’s due-date range from a mating date and gestation length.
Last updated · View algorithm, constants and default inputs (JSON)
Results
About this calculator
Estimate a cat’s due date from the mating date and a selected gestation length. Merck reports that pregnancy lasts about 60–65 days and delivery commonly occurs around 64–66 days after breeding; the mating date may not match conception. This estimate cannot confirm pregnancy or predict delivery. Ask a veterinarian about an individual cat.
Worked example
calculated with the default values below
Mating date 2026-10-31 · Gestation length 65 days Estimated due date 2027-01-04 · Early date estimate 2026-12-30 · Late date estimate 2027-01-05 · Days since mating 0 days · Days remaining 65 days
General background references
Disclaimer
These calculators offer general guidance and do not replace veterinary advice. Individual animals vary with breed, weight, health status and medication. Suspected poisoning from chocolate, medication, plants or chemicals is an emergency — contact your veterinarian or a pet poison control service immediately rather than relying on a calculator.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
Estimated due date = mating date + G days; planning window = mating date + 60 to 66 days
- mating date
- entered mating date
- G
- selected gestation estimate (days; 60–66)
Feline gestation is commonly about 60–66 days, often near 64–66 days after breeding. The mating date may not match conception; this is a planning estimate, not a pregnancy or labor diagnosis.
Frequently asked questions
How is the cat due-date range estimated?
The selected number of days sets the central estimate. This page shows a broader 60–66-day planning window because the mating date may not be the conception date. Merck notes that delivery commonly occurs around 64–66 days after breeding. A calendar estimate cannot confirm pregnancy or predict labor.