If Your Dog Was Born in 2019, 2020, or 2021 - How Old Now?
Birth-year examples mapped to human years for small, medium, large, and giant breeds.
Cat & Dog Age Calculators
Free cat age and dog age calculators that convert birthday, weeks, or months into human years. Pick the right tool below - whether you need a kitten week converter, a puppy month chart, or breed-adjusted dog years.
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Which calculator should I use?
Match your situation to the canonical tool - each calculator uses a different input (birthday, weeks/months, or breed) but the same veterinary aging formulas.
| Your situation | Recommended tool |
|---|---|
| I know my dog's birthday | Dog Age Calculator by Birth Date |
| I know my cat's birthday | Cat Age Calculator by Birth Date |
| I have a puppy's age in weeks or months | Dog Age Calculator by Months and Weeks |
| I have a kitten's age in weeks or months | Cat Age Calculator by Months and Weeks |
| I know my dog's breed and age in years | Dog Age Calculator by Breed |
| I want to predict my puppy's adult weight | Puppy Growth Calculator |
| I need vaccination due dates for a new pet | Pet Vaccination Schedule Calculator |
Dog Age Calculator
Convert dog years to human years by birthday, puppy weeks, or breed. Size-adjusted formulas follow AAHA life-stage guidelines - small breeds age slower than giant breeds after year two.
Dog Age Calculator by Birth Date
Enter your dog's birth date to get exact human years, life stage, and a personalized care milestone calendar. Size-adjusted for small through giant breeds.
Dog Age Calculator by Months and Weeks
Convert puppy or adult dog age from weeks and months into human years. Ideal when you know age but not the exact birth date.
Dog Age Calculator by Breed
Convert dog age to human years by breed with AAHA size-adjusted aging for Chihuahuas, Labs, Great Danes, and 100+ breeds.
Cat Age Calculator
Convert cat years to human years from a birthday or kitten age in weeks. The standard curve maps year one to about 15 human years and year two to about 24, then roughly +4 per year after that.
Cat Age Calculator by Birth Date
Enter your cat's birth date for exact human years, kitten-to-senior life stage, and upcoming vaccination and care milestones.
Cat Age Calculator by Months and Weeks
Convert kitten or adult cat age from weeks and months into human years. Supports breed and indoor/outdoor lifestyle inputs.
Puppy Growth, Weight & Pet Cost Calculators
Tools for predicting adult dog size, checking healthy weight ranges, planning vaccinations, and estimating food and insurance costs.
Puppy Growth Calculator
Predict adult dog weight from current age, weight, and expected breed size with growth curve estimates.
Pet Vaccination Schedule Calculator
Generate personalized dog and cat vaccination schedules from birth or adoption date with due dates for core vaccines.
Dog Weight Calculator
Find healthy weight range for dogs by breed size and age with body condition score guidance.
Cat Weight Calculator
Find healthy weight range for cats by age and breed type with body condition score guidance.
Pet Food Cost Calculator
Calculate monthly, annual, and lifetime pet food costs by pet type, size, and daily portions.
Pet Insurance Cost Estimator
Estimate monthly pet insurance premiums by species, age, breed size, and coverage level.
Frequently Asked Questions
- How do I calculate my cat's age in human years?
- Use the Cat Age Calculator by Birth Date if you know the birth date, or the Cat Age Calculator by Months and Weeks if you only know age in weeks or months. Both apply the standard veterinary curve: about 15 human years in year one, 24 by year two, then roughly +4 per cat year after that.
- How do I calculate my dog's age in human years?
- Use the Dog Age Calculator by Birth Date for an exact date, Months and Weeks for puppies, or Breed if you know the breed and calendar age. Dogs age faster in the first two years (~24 human years by age two), then slow down based on size - small breeds add about +4 human years per year, giant breeds about +7.
- Which pet age calculator should I use?
- Start with birthday if you have it - that gives the most precise human-year conversion and milestone calendar. Use weeks/months for young puppies and kittens when the exact birth date is unknown. Use the breed calculator when you know the breed name and age in whole years.
Related Guides
Source-checked explainers for birth-year estimates, puppy month charts, and breed-size aging comparisons.