🐾 Free pet planning tool

Pet Age & Life Stage Calculator

Discover your dog or cat’s approximate physiological age, current life stage, and the care topics that deserve extra attention right now.

1. Tell us about your pet

The name is optional, but it makes the care plan more personal.

Pet name Pet type

Current age

Years Additional months

2. Choose your dog’s size

Size affects the age comparison and the approximate point at which a dog may enter the senior stage.

🐕 Small Up to 20 lb / 9.1 kg

🐕 Medium 21–50 lb / 9.5–22.7 kg

🐕 Large 51–90 lb / 23.1–40.8 kg

🐕 Giant Over 90 lb / 40.8 kg

Personalized result

Pet life stage summary

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Enter your pet’s age to begin.

The estimated human-equivalent age and care plan will appear here.

Pet age 0 years

Approx. human-equivalent age 0 years

Progress through this stage 0%

Care priorities for this stage

Questions for the next veterinary visit

Changes worth monitoring

How the estimate is calculated

Cat stages follow the AAHA/AAFP feline life-stage definitions. Dog stages are based on AAHA’s developmental definitions, with a practical size-based estimate for the beginning of the senior period. Human-equivalent ages are approximate comparisons, not measures of health or expected lifespan.

Age is only one factor Breed, body size, genetics, health history and lifestyle can all affect how an individual pet ages.

Watch the individual pet Changes in appetite, thirst, mobility, behavior or bathroom habits matter more than a number alone.

Use the result as a conversation starter A veterinarian can recommend an examination and screening plan suited to the individual animal.

Educational sources: AAHA Canine Life Stage Definitions, AAHA/AAFP Feline Life Stage Guidelines, and AAHA physiological age chart.

Important: This calculator is for general education only. It cannot diagnose disease, determine exact biological age, predict lifespan or replace veterinary advice.