The TNR PRO cat calculator estimates cat population growth if cats are not sterilized through
Trap-Neuter-Return (permanent birth control for unfixed, free-roaming outdoor cats) or spay/neuter
at any local veterinarian. It is meant to demonstrate the urgent need for permanent birth control
to prevent the reproduction of more unfixed kittens and cats born outside.
Remember, cats don’t add. They multiply!
Fixing the stray cats you feed is crucial for several reasons:
Population Control: Spaying and neutering helps prevent the birth of countless homeless kittens, reducing their population.
Health Benefits: Fixed cats are less prone to certain health issues, which can lead to a healthier community of cats and fewer veterinary costs for caregivers.
Behavior Improvement: Fixed cats exhibit better behavior, making them easier to care for and reducing stress in their environment.
Community Impact: Reducing the number of stray cats helps improve the overall health and safety of the community, lowering the risk of diseases and accidents.
Resource Allocation: Fewer cats mean less strain on local shelters and resources, allowing them to focus on other important animal welfare initiatives.
By fixing the stray cats you feed, you not only improve their lives but also create a positive ripple effect in your community and neighborhood.
Results
Year
Estimated Cat Population
🔺 Assumptions
Initial population (N₀) = number of unfixed cats you are currently feeding
Cats can get pregnant at four months of age
Mature females: can have up to 6 litters/year at 4 kittens/litter
Immature females: first litter is usually smaller, averaging two kittens
Kittens Born Outside Survival Rate: 25% for the first year
No spaying or neutering (no birth control applied)
Unlimited resources (food, water, shelter)
Years you plan to feed them without fixing them = X years
📌 Disclaimer
The TNR PRO Stray Cat Calculator is a mathematical model based on simplified assumptions about feline
reproduction, survival, and population dynamics. It is intended for general informational purposes only
and should not be relied upon for precise predictions or management decisions in real-world scenarios.
Actual cat populations may vary significantly due to factors such as limited food or habitat, disease,
predation, human interventions (e.g., trapping or feeding), seasonal breeding variations, or other
environmental constraints not accounted for in the model.
The model assumes exponential growth, which may not hold for long periods due to carrying capacity limits.
Users should consult with veterinarians, ecologists, or local animal control authorities for accurate
assessments and management strategies for stray cat populations. The model’s results are approximations
and should be interpreted with caution, especially for long timeframes or specific local conditions.