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Comparison of Dog Ages

by Ron Kurtus (updated 27 November 2022)

Dogs age more rapidly than humans. One year for a dog is equivalent to between five and eight years of human life, depending on the size of the animal.

A dog has different nutritional and health care needs in the various phases of its life. Older dogs suffer from the same ailments as elderly people, such as arthritis and loss of hearing and vision. You can get a good idea of how to take care of your dog and also understand its behavior by examining the comparison of the actual age of your dog and the corresponding age of a human.

The same is true for cats and other animals.

Questions you may have include:

This lesson will answer those questions. Animal Health Disclaimer

Ages of dogs

Since dogs can vary from weighing only a few pounds to over 100 pounds, size is a major factor in the animal's longevity. Productive years are when the dogs are able to reproduce.

Also see: Dog Age Calculator - With respect to breed and weight

  Age 2-20 pounds 20-50 pounds 50-90 pounds >90 pounds
Pup 1-11 months Juvenile Juvenile Juvenile Juvenile
  1 year 12 years 12 years 16 years 20 years
Productive Years 2 years 19 years 21 years 23 years 26 years
  3 years 25 years 25 years 29 years 34 years
  4 years 32 years 32 years 35 years 42 years
  5 years 35 years 36 years 39 years 50 years
  6 years 40 years 42 years 45 years 56 years
  7 years 44 years 48 years 50 years 62 years
  8 years 48 53 56 68
  9 years 53 58 62 74
  10 years 57 62 67 80
Middle Age 11 years 63 66 72 86
  12 years 67 70 77 93
  13 years 70 74 82 101
  14 years 73 78 88 108
  15 years 76 83 93 115
  16 years 80 87 99 123
Elderly 17 years 84 92 104  
  18 years 88 96 109  
  19 years 92 101 115  
  20 years 96 105 123  
  21 years 99 109    
  22 years 102 113    
  23 years 104 117    
  24 years 107      
  25 years 109      
  26 years 112      

Ages of cats

See: Comparison of Cat Ages.

Ages of various animals

See: Comparison of Animals Ages.


Most pets and other animals have a shorter life span that humans. With dogs and cats, a relationship between their age and the equivalent human age has been estimated. As they age, they require different care, as do humans when they age.

Dogs are wonderful companions

Resources and references

Ron Kurtus' Credentials


Pet doctor - animal life span

Pet Health Resources


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Top-rated books on Pet Health

Top-rated books on Caring for an Older Dog

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