Small (20 lbs or less)
Medium (21-50 lbs)
Large (51-90 lbs)
Giant (Over 90 lbs)
Result:
How Pet Age is Calculated
The old "7 human years for every 1 dog year" rule is a myth. Science shows that pets age much faster in their first two years of life and then the rate levels off. Furthermore, for dogs, size plays a massive role in longevity and aging speed.
Dog Aging Factors: Small breeds generally live longer than large breeds. A 10-year-old Chihuahua is middle-aged, whereas a 10-year-old Great Dane is considered very elderly.
Cat Aging Factors: Cats age fairly consistently. The first year of a cat's life is roughly equal to 15 human years, and the second year adds about 9 more. After that, each calendar year is about 4 human years.
Comparison Examples
1 Year Old Dog: Equivalent to a 15-year-old teenager.
5 Year Old Cat: Equivalent to a 36-year-old adult.
10 Year Old Large Breed Dog: Equivalent to a 75-year-old senior.
Signs of Aging in Pets
Keep an eye out for these common signs that your pet is entering their "senior" years:
Cloudy eyes or difficulty seeing.
Slower movement or stiff joints in the morning.
Changes in sleep patterns or increased vocalization.
Weight changes or dental issues.
function toggleSizeSelector() {
var petType = document.getElementById("petType").value;
var sizeWrap = document.getElementById("sizeSelectorWrap");
if (petType === "dog") {
sizeWrap.style.display = "block";
} else {
sizeWrap.style.display = "none";
}
}
function calculatePetAge() {
var type = document.getElementById("petType").value;
var age = parseFloat(document.getElementById("calendarAge").value);
var size = document.getElementById("dogSize").value;
var resultDiv = document.getElementById("petAgeResult");
var resultText = document.getElementById("petAgeOutputText");
var humanYears = 0;
if (isNaN(age) || age < 0) {
alert("Please enter a valid age.");
return;
}
if (type === "cat") {
if (age === 0) {
humanYears = 0;
} else if (age <= 1) {
humanYears = age * 15;
} else if (age <= 2) {
humanYears = 15 + ((age – 1) * 9);
} else {
humanYears = 24 + ((age – 2) * 4);
}
} else {
// Dog Logic based on AVMA and American Kennel Club guidelines
if (age === 0) {
humanYears = 0;
} else if (age <= 1) {
humanYears = 15;
} else if (age <= 2) {
humanYears = 24;
} else {
var multiplier = 4;
if (size === "small") multiplier = 4;
if (size === "medium") multiplier = 5;
if (size === "large") multiplier = 7;
if (size === "giant") multiplier = 9;
humanYears = 24 + ((age – 2) * multiplier);
}
}
var roundedYears = Math.round(humanYears * 10) / 10;
var animalName = (type === "dog") ? "Dog" : "Cat";
resultText.innerHTML = "Your " + age + " year old " + animalName + " is approximately " + roundedYears + " years old in human years.";
resultDiv.style.display = "block";
}