Dog Age Calculator by Breed

How old is my dog in human years?

A quick rule of thumb: a dog’s first year equals about 15 human years, the second year adds about 9 more (so a 2-year-old dog is about 24), and each year after that adds roughly 4–5 years for small dogs and 6–7 years for large and giant dogs, because bigger breeds age faster. For your dog’s exact figure, use the calculator above or find their age and size in the chart below.

Dog age chart: dog years to human years

This is the size-based chart the calculator uses, popularized by the American Veterinary Medical Association. Find your dog’s age on the left and their adult size along the top.

Highlighted values mark roughly when dogs of that size are considered seniors.

How dogs really age

Dogs race through childhood. By their first birthday most dogs are physically like a mid-teen human: sexually mature, nearly full-grown, and full of adolescent energy. Year two adds roughly another nine human years. After that the pace slows to about 4–7 human years per dog year, depending mostly on size.

That’s why a single multiplier can’t work. A 10-year-old Yorkshire Terrier is roughly 56 in human terms, while a 10-year-old Great Dane is closer to 80.

Breeds by size category

Not sure which size to choose? Here’s where common breeds usually fall, based on typical adult weight:

Small (up to 20 lb / 9 kg)

Affenpinscher, Bichon Frise, Border Terrier, Boston Terrier, Cairn Terrier, Cavalier King Charles Spaniel, Chihuahua, Dachshund, French Bulldog, Havanese, Italian Greyhound, Jack Russell Terrier, Lhasa Apso, Maltese, Miniature Pinscher, Miniature Schnauzer, Papillon, Pekingese, Pomeranian, Poodle (Miniature), Poodle (Toy), Pug, Shetland Sheepdog, Shiba Inu, Shih Tzu, West Highland White Terrier, Yorkshire Terrier. Typical lifespan: 12–16 years; senior from about 10 years.

Medium (21–50 lb / 10–23 kg)

American Staffordshire Terrier, Australian Cattle Dog, Australian Shepherd, Basenji, Basset Hound, Beagle, Border Collie, Brittany, Bull Terrier, Bulldog (English), Chow Chow, Cocker Spaniel, Corgi (Pembroke), Dalmatian, English Springer Spaniel, Labradoodle (standard), Pit Bull Terrier, Poodle (Standard), Samoyed, Siberian Husky, Staffordshire Bull Terrier, Standard Schnauzer, Vizsla, Whippet. Typical lifespan: 10–14 years; senior from about 8 years.

Large (51–100 lb / 23–45 kg)

Airedale Terrier, Akita, Alaskan Malamute, American Bulldog, Bernese Mountain Dog, Bloodhound, Boxer, Collie, Doberman Pinscher, German Shepherd, German Shorthaired Pointer, Golden Retriever, Goldendoodle (standard), Greyhound, Irish Setter, Labrador Retriever, Rhodesian Ridgeback, Rottweiler, Weimaraner. Typical lifespan: 9–12 years; senior from about 7 years.

Giant (over 100 lb / 45 kg)

Bullmastiff, Cane Corso, Great Dane, Great Pyrenees, Irish Wolfhound, Mastiff, Newfoundland, Saint Bernard. Typical lifespan: 7–10 years; senior from about 5 years.

Want breed-specific care tips? Read our profiles of the Labrador Retriever, German Shepherd, Beagle and Yorkshire Terrier.

Caring for your dog at every life stage

• Puppy (0–1 year): vaccinations, socialization before about 16 weeks, house training and crate training.
• Adolescent (1–2 years): energy peaks and training can seem to regress. Stay consistent and increase mental exercise.
• Adult: annual checkups, dental cleaning, and keeping a lean body weight, the single biggest lifespan factor you control.
• Senior: vet visits every six months, joint-friendly exercise, softer bedding, and watching for changes in thirst, appetite, weight or behavior.

This calculator gives an estimate for curiosity and care planning. It isn’t a medical assessment. Your vet can tell you how your individual dog is aging.