Formula using the 15-9-4 model:
• Year 1: = 15 human years
• Year 2: = 9 additional human years (total 24)
• Each subsequent year: = 4 human years

This model accounts for rapid early development in cats and is recommended by the International Cat Care and American Association of Feline Practitioners.

This formula is the current veterinary standard as of 2025. Factors like breed, lifestyle (indoor/outdoor), diet, and health can influence actual aging.

Recommended by: International Cat Care and American Association of Feline Practitioners