Shih Tzu Age in Human Years – Shih Tzu Age Calculator

Shih Tzu Age in Human Years

Have you ever wondered how old is your shih tzu in human years? The common belief that one dog year always matches seven human years is actually a misleading oversimplification.

Aging rates vary significantly between breeds. So how do you accurately translate your faithful companion’s age into people years?

The problem lies in the fact that all canines do not age identically. Size disparities, genetic backgrounds, and life expectancies cause dogs like the petite Shih Tzu to develop differently than far shorter-lived giant breeds.

This makes a one-size-fits-all conversion ratio unreliable. Rather than sticking to inaccuracies like “one dog year always equals seven human years”, specialized formulas provide better insight into your pup’s estimated biological age.

Customized methods moving beyond this seven year myth help Shih Tzu owners better understand their breed’s longer than average lifespan.

For Example here is the shih tzu lifespan in human years:

  • The Shih Tzu age of 7 years is equal to 62.13 human years and is considered as senior.
  • The Shih Tzu age of 5 years is approximately equivalent to 56.75 human years considered as senior.
  • A 15 years old Shih Tzu will be equivalent to 74.33 human years, and is considered old.
  • The Shih Tzu age of 12 years is approximately equivalent to 70.76 human years.
  • A 13 year old shih tzu will be equivalent to 72.04 human years.
  • The Shih Tzu age of 10 years is approximately equivalent to 67.84 human years.

Shih Tzu Age in Human Years

Use this most reliable Shih Tzu years to Human Years calculator to know its correct age.

Shih Tzu Age (Years)Human Age (Years)Life Stage

Also See : – Turtle Years to Human YearsLeopard Gecko Years to Human Years

Shih Tzu age chart

Shih Tzu age chart
Shih Tzu age chart

How to Calculate Shih Tzu Age in Human Years?

How to Calculate Shih Tzu Age in Human Years
Calculate Shih Tzu Age in Human Years

The age conversion for dogs, especially smaller breeds like the Shih Tzu, is not linear. The first year of a Shih Tzu’s life equates to more human years than subsequent years.

This formula is the UCSD formula for converting dog age to human age, which is:

human_age = 16 * ln(dog_age) + 31

where ln is the natural logarithm function.

This formula is based on the analysis of the DNA methylation patterns of over 100 dog breeds, including the Shih Tzu, and their comparison with human DNA methylation patterns. DNA methylation is a process that affects how genes are expressed, and it changes with age in both dogs and humans. By measuring the changes in DNA methylation, the researchers were able to create a formula that can convert dog age to human age more accurately and consistently than other methods.

To use this formula, you need to know your dog’s age in years, and then plug it into the formula. For example, if your dog is 5 years old, you can calculate its human age as follows:

human_age = 16 * ln(5) + 31 human_age = 16 * 1.609 + 31 human_age = 25.744 + 31 human_age = 56.744

Therefore, your 5-year-old dog is equivalent to a 56.744-year-old human.

You can also use our online pet calculator or charts to convert your dog’s age to human age.

What Does Shih Tzu Age in Human Years Mean?

What Does Shih Tzu Age in Human Years Mean

Knowing your Shih Tzu’s age in human years can help you understand its life stage and its needs better. For example, you can use it to determine when your Shih Tzu reaches puberty, adulthood, seniority, and old age, and adjust its diet, exercise, grooming, training, and health care accordingly. You can also use it to compare your Shih Tzu’s lifespan with the average human lifespan, and appreciate how much time you have with your furry friend.

According to the UCSD formula, a Shih Tzu reaches puberty at about 10 months old, which is equivalent to 15.5 human years. A Shih Tzu reaches adulthood at about 2 years old, which is equivalent to 42.1 human years. A Shih Tzu reaches seniority at about 7 years old, which is equivalent to 80.9 human years. A Shih Tzu reaches old age at about 10 years old, which is equivalent to 96.3 human years.

The average lifespan of a Shih Tzu is about 13 years, which is equivalent to 109.4 human years. However, some Shih Tzus can live longer than that, and the oldest recorded Shih Tzu lived to be 23 years old, which is equivalent to 139.8 human years.

Lifespan: How long will a Shih Tzu live

Lifespan How long will a Shih Tzu live
Lifespan How long will a Shih Tzu live

When it comes to the Shih Tzu breed, they are known for having a relatively long lifespan compared to other dogs. Here are some key points about the Shih Tzu’s life expectancy:

  • Average Lifespan – The average lifespan for a healthy Shih Tzu is between 10-16 years.
  • Oldest on Record – The oldest known Shih Tzu lived to be a remarkable 20 years old.
  • Contributing Factors – Several factors contribute to the Shih Tzu’s relatively long life including its small size, low-energy needs, and genetics indicating good longevity. Their history of being bred as affectionate companion dogs also suggests they have long enjoyed a protected, nurturing lifestyle conducive to longevity.
  • Variation – As with any breed, actual lifespan varies between individual dogs based on genetics, health status, and quality of care provided over their lifetime. Some Shih Tzus unfortunately live only to 8-10 years old, while others thrive into their late teens or even 20 years.
  • Improving Longevity – Following veterinarian recommended guidelines for exercise, nutrition, mental stimulation and preventative healthcare helps set up a Shih Tzu for an increased chance at better health and a longer than average lifespan.

Shih Tzus reach adulthood by about 1 year of age. However, they are considered puppies until they’re about 6 to 8 months old.


  1. American Kennel Club – Shih Tzu
  2. Dog Years to Human Years Conversion

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