Conversion to “human years”:
• cat — first 2 years ≈ 24 human, then +4 per year;
• dog — first 2 years ≈ 24 human, then: small +4, medium +5, large +6, giant +7 per year;
• other species — proportional to expected lifespan (normalized to 80 human years).
Convert your pet's age to human years based on species and size. Enter a birth date for an accurate age breakdown in human-equivalent years.