Pet Age Calculator
Based on AAHA 2020 research — no more outdated "× 7" myth
Formula: UC San Diego / AAHA 2020 study
Quick guide
What can Pet Age Calculator help you do?
Free pet age calculator using AAHA 2020 research (not the outdated × 7 myth). Supports cats and dogs with size adjustment.
Best for
Useful for quick file work, text cleanup, calculations, content creation, and website or AI checks.
How to use it
Open the tool, enter or upload what it asks for, then copy or download the result directly.
Privacy and limits
Most tools run in your browser with no sign-in. Very large files or older devices may hit browser memory limits.
Frequently Asked Questions
Why isn't dog age just "× 7"?
The "× 7" rule is a 1950s rough estimate. UC San Diego 2020 research showed dog aging is logarithmic, not linear. Formula: human age = 16 × ln(dog age) + 31.
How is cat age calculated?
Cat standard: Year 1 = 15 years, Year 2 = 24 years, then +4 per year.
Do different dog sizes age the same?
No. Large breeds (> 25 kg) age faster, lifespan 8–10 years. Small breeds can live 14–16 years. We adjust for size.
My puppy is 6 months old, how to calculate?
Set "Age" to 0 and "Extra months" to 6. Puppy aging is handled separately (non-linear).
How are life stages categorized?
Puppy/Kitten (< 1 yr), Young Adult (1–3), Adult (3–7), Senior (7–10), Geriatric (> 10). Common veterinary standard.