Collie Age Calculator
Convert your Collie's age to human years, adjusted for large-breed aging. Life expectancy 12–14 years.
Last reviewed July 2026 · Free · Nothing you enter is stored
large breed
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Educational estimate for a large breed. Individual dogs vary — your vet is the best judge of your Collie's life stage.
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About Collie aging
The Collie is a large breed with a typical adult weight of 50–75 lbs and a life expectancy of 12–14 years. Because aging speed tracks body size, this page uses the large-breed rate — a middle rate.
Frequently asked questions
How do you calculate a Collie's age in human years?
As a large breed, the Collie ages at the large-breed rate: about 15 human years in year one, 24 by age two, then roughly 5.5 human years for each dog year after that. Enter an age above to see the exact figure alongside the UCSD epigenetic estimate.
How long do Collies live?
The typical Collie life expectancy is 12–14 years. Keeping your dog at a healthy weight, staying current on veterinary care, and dental hygiene are the biggest levers on the high end of that range.
When is a Collie considered a senior?
Large and giant breeds like the Collie reach senior status early — around age 6–7. Senior care means more frequent vet checks and often a diet adjustment.
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