Pet Age to Human Years Calculator

Convert your pet's age into equivalent human years based on species and size/breed category.

Formulas Used

Dogs (AVMA): Year 1 = 15 human yrs · Year 2 = +9 human yrs · Each additional year = +4 (small) / +5 (medium) / +6 (large) / +7 (giant) human yrs.

Cats (International Cat Care): Year 1 = 15 · Year 2 = +9 · Each additional year = +4 human yrs.

Rabbits (House Rabbit Society): Year 1 = 18 · Year 2 = +14 · Each additional year = +6 human yrs.

Guinea Pigs: 1 guinea pig year ≈ 14 human years.

Hamsters: 1 hamster year ≈ 25 human years.

Small Birds (Budgie/Canary): 1 bird year ≈ 6 human years.

Large Parrots: 1 parrot year ≈ 1.2 human years.

Assumptions & References

  • Dog formula based on American Veterinary Medical Association (AVMA) guidelines; size categories affect aging rate after year 2 because larger breeds age faster.
  • Cat formula from International Cat Care (iCatCare) / Feline Advisory Bureau life-stage chart.
  • Rabbit formula from the House Rabbit Society age-equivalency guide.
  • Guinea pig, hamster, and bird ratios are derived from average species lifespan compared to average human lifespan (~79 years).
  • Large parrot lifespans (50–80 years) are close to human lifespans, so the ratio is near 1:1.
  • Fractional ages (e.g., 0.5 years) are supported and scaled linearly within each age bracket.
  • These are estimates; individual animals vary based on genetics, diet, and veterinary care.

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