Pet Age Converter
Convert cat and dog ages into human-year estimates by species and body size, with life stages, care priorities and reference lifespans.
Enter a cat or dog age to see an approximate human-age equivalent, its life stage, care priorities and a reference lifespan. This is a rough everyday guide, not a medical assessment.
Pet age
Results update as you type.
Result
Care priorities at this stage
Conversion table, ages 1 to 20
Values follow the common conversion rules and are rounded to whole numbers; individual aging varies.
| Pet age | Cat | Small dog | Medium dog | Large dog | Giant dog |
|---|
Why not simply multiply by seven?
The first two years pass quickly. Cats and dogs reach sexual maturity around one year and are largely fully grown by two, so the early years cannot follow a fixed multiplier.
After age two, body size starts to matter. Each extra year is roughly 4 human years for a small dog, 5 for a medium dog, 6 for a large dog and 7 for a giant dog; for a cat it is about 4. Larger animals usually age faster and have shorter reference lifespans.
Five common myths
Myth 1: a dog year equals seven human years
The times-seven rule is a popular shortcut. It ignores fast early maturation and the later split by body size, so the error can be large.
Myth 2: cats and dogs share one formula
Cats and dogs mature at different rates, and dog sizes differ too. A small dog and a giant dog can age almost twice as fast as each other, so one coefficient cannot fit all.
Myth 3: body size does not affect lifespan
Body size is one of the strongest factors in dog lifespan. In population data, small dogs usually live longer than large and giant dogs, though individual variation remains.
Myth 4: teeth give an exact age
Tooth wear depends on diet, chewing habits, dental care and individual variation, so it is only a rough clue. Accurate age usually needs birth records, bone assessment and a vet exam.
Myth 5: lifespan can be predicted exactly
Lifespan ranges come from population statistics and only describe a broad range. Genetics, weight, neutering, dental health, exercise and medical care all affect an individual animal.
Checkup guidance by life stage
General guidance only; follow your vet for specific tests and frequency.
| Life stage | Checkup frequency | Focus areas |
|---|---|---|
| Baby | Monthly during vaccination and deworming, then once a year | Temperature, weight curve, vaccine and deworming records, baby teeth |
| Young | Once a year | Weight and body condition, skin and coat, mouth, joints and mobility |
| Adult | Once a year, then every 6–12 months in the senior stage | Blood and urine tests, heart auscultation, teeth and tartar, weight and body condition |
| Senior | Every 6–12 months | Kidney function, heart, joints, thyroid, teeth, vision and hearing |