Use the free Multi-Species Age Calculator to estimate a pet’s human-equivalent age. Dogs and cats use non-linear, species-specific models; other species use a transparent lifespan-scaling heuristic.
Pet Age → Human Years (Dogs, Cats, Rabbits, Birds, Snakes, Turtles)
- Dogs: first 2 years ≈ 24 human years; after that depends on size (small +4.0, medium +4.6, large +5.3 per year).
- Cats: year 1 ≈ 15; year 2 ≈ 24; then +4 per year.
- Other species: heuristic lifespan-scaling to 80 human years. Results are estimates.
See dedicated tools: Dog Age · Cat Age · Back to All Pet Calculators · Shop: WVPet.
How the Multi-Species Age Calculator Works
Pets age at different biological rates. A single “x7” rule cannot capture the rapid early development seen in dogs and cats or the wide lifespan variation in rabbits, birds, snakes, and turtles. This page offers a practical, transparent way to estimate a pet’s human-equivalent age so you can better understand life stage and plan care.
Species Models We Use
Dogs: The first two dog years approximate 24 human years. After year two, aging depends on body size—small breeds age more slowly than large/giant breeds. A typical rule of thumb adds ~4.0 (small), ~4.6 (medium), or ~5.3 (large) human years per dog year. Background: AKC overview and Aging in dogs (Wikipedia).
Cats: Year 1 ≈ 15 human years; year 2 ≈ 24; each additional year ≈ +4. This simple, non-linear curve aligns with widely used veterinary guidance. See Cornell Feline Health Center and Aging in cats.
Other species: Because lifespans vary widely, we use a clear heuristic:
human-equivalent ≈ (pet age / typical species lifespan) × 80.
This expresses a pet’s progress through its expected lifespan on an ~80-year human scale.
You can adjust the lifespan field to reflect your specific species and husbandry. Useful references:
animal longevity list,
turtles,
parrots,
snakes,
domestic rabbits.
Why Age Conversion Helps
- Preventive care: Align wellness exams, vaccines, and screening tests with your pet’s life stage.
- Nutrition & activity: Senior pets often need calorie adjustments, joint support, or gentler enrichment.
- Owner expectations: A human-equivalent age provides an intuitive frame for behavior and mobility changes.
Limitations and Good Practices
Any conversion is an estimate. Genetics, body condition, environment, and prior medical history can shift real-world aging. Use this tool alongside veterinary advice and credible nutrition resources such as the WSAVA Global Nutrition Guidelines and general care pages from the AVMA. If your pet has a chronic disease, follow your veterinarian’s individualized plan.
Related Tools
Try the dedicated calculators for Dog Age and Cat Age, or explore all pet calculators. Looking for a gift? Visit the WVPet Shop for personalized pet items.