Puppy
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Dog age calculator
How old is your dog, really?
Get an approximate human-age equivalent and canine life stage using your dog’s age and adult size. The estimate uses published veterinary guidance instead of multiplying every year by seven.
- Size-aware
- Sources explained
- Private in your browser
Try the calculator
Enter your dog’s age and size.
Use their expected or current healthy adult weight. Mixed breeds can use the closest size band.
Your estimate
Ready when you are.
Enter an age and adult size to see an approximate human-age equivalent and life stage.
Approximately
36human-age years
Estimated life stage
Mature adult
- Puppy
- Young adult
- Mature adult
- Senior
How this result was calculated:
A transparent estimate
Why this is more useful than the seven-year rule.
The AAHA chart estimates every dog at about 15 human-age years on the first birthday and 24 on the second. After that, it provides different values for small, medium, large, and giant dogs. [1]
AAHA recommends thinking in life stages rather than treating human-age conversion as an exact biological fact. Its stages consider age alongside size, breed, lifestyle, and health. [2]
How the estimate is calculated
AAHA size chart + interpolation between birthdays
The result is rounded to a whole number. It is an educational comparison, not a biological age or lifespan prediction.
- 01Choose the size column
The four weight bands match the published AAHA chart.
- 02Read the nearest birthdays
For an age between whole years, the calculator blends the two surrounding chart values.
- 03Estimate a life stage
Puppy and young-adult boundaries follow AAHA guidance. The senior estimate uses the final quarter of a typical lifespan, with size context from a large clinical study. [3]
Canine life stages
Age is most helpful when it guides the next conversation.
AAHA’s framework gives pet families and veterinary teams a shared starting point. Boundaries are gradual, and an individual dog may not match the estimate exactly.
Young adult
Physical and social maturation continues after the fastest growth period ends.
Mature adult
The longest stage for many dogs, with needs shaped by breed, lifestyle, and health.
Senior
A broad stage where individual assessment matters more than a birthday alone.
Common questions
What a dog age estimate can and cannot tell you.
Why not multiply by seven?
A one-year-old dog is far more developed than a seven-year-old child, so one fixed multiplier misses early growth and later size differences.
Why does adult size matter?
Peer-reviewed studies find that larger dogs generally have shorter life expectancy than smaller dogs. Breed and individual health still matter. [3]
Is the result exact?
No. It is a friendly comparison based on a published chart. It cannot measure biological age or predict how long an individual dog will live.
Educational only. This calculator cannot assess your dog’s health, predict lifespan, or replace veterinary advice. Ask your veterinarian about life-stage care, screening, nutrition, exercise, and any change in behavior or health.
Sources and review notes
Built from veterinary guidance and primary research.
Last reviewed July 28, 2026. Voffi presents these sources for transparency and does not claim that human-age conversion is a clinical measurement.
- AAHA Canine and Feline Physiological Age Chart
Official approximate human-age values for four adult dog weight bands.
- AAHA Canine Life Stage Definitions
Official definitions for puppy, young adult, mature adult, and senior stages, including the role of size and breed.
- Life expectancy tables for dogs and cats derived from clinical data
Peer-reviewed clinical life tables with adult dog body-size bands. Frontiers in Veterinary Science, 2023.
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