Free dog age calculator
How old is your dog, really?
Forget multiply-by-seven. tailculator uses real, breed-specific lifespan data to give you your dog's true age in human years — in one tap.
- 43 breeds
- Cited sources
- Free · no signup
Biscuit · Golden Retriever → BASED ON AKC BREED DATA
A Chihuahua and a Great Dane don't age the same
Body size drives how fast a dog ages — small breeds race through puppyhood then plateau; giants age fast throughout. That's why tailculator asks for the breed, not just the years.
Chihuahua · age 6 40 human years 
Great Dane · age 6 59 human years Find your dog
Pick a breed for its life stages, typical lifespan, and a breed-accurate age chart.
Dive into dog aging
Field-guide explainers on growth, life stages, and breed-specific aging.
- When Is a Chihuahua Full Grown? Chihuahuas are full grown at about 9 months, with most reaching adult size between 6 and 12 months. Growth chart by age, plus when they stop growing.
- When Is a German Shepherd Full Grown? A German Shepherd reaches full height by about 18 months but fills out in chest and muscle until 2 to 2.5 years. Growth chart by age inside.
- When Is a Golden Retriever Full Grown? A Golden Retriever is full grown at about 2 years old. It reaches near-adult height by 12 months, then fills out with muscle through the second year.
- When Is a Labrador Full Grown? A Labrador is full grown at about 18 months: near-adult height by 12 months, then filling out in muscle. Growth chart by age and the size differences.
Three taps to a real answer
- 1Pick your dog's breed. Or choose "mixed" and we'll use weight.
- 2Enter their age. In years — puppies and seniors both welcome.
- 3Get a real answer. Breed-accurate, cited, and ready to share.