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Comment by asdfman123 | Hacker News Reader

The best thing I learned from this article: to calculate a dog's human age, you don't multiply their age times 7 (7x). You use the following formula:

ln(x)*16+31

It makes sense, because a 1-year-old dog definitely seems much more grown up than a 7 year old kid.

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I think you need to take the dog's weight and breed into account. Something like: https://www.akc.org/expert-advice/health/how-to-calculate-do....

Anecdotally I'm assuming this equation must be breed-specific because I've had a number of dogs 8+ years old that did not appear to act or look very senior.

I think it has to be because I've heard small dogs age more slowly. Maybe there's a way to adjust for weight/breed that I could find if I were willing to dig through the original research paper.

Playing around with the numbers a bit, I think it's pretty seriously wrong.

A 6-month old dog is still a child, in dog terms. This formula says they're nearly 20 years old; I'd be inclined to say that the "right" answer is more like 15 years, if not less.

A 1-year old dog is beyond adolescence but is still maturing, but this formula says they're 31 years old, well into adulthood.

A 5-year old dog is in the prime of their life; this formula says they're 56 years old, well into the range of what we'd consider a senior.

A 30-year old dog would set a new world record. (The oldest dog known was about 29.5 years old.) This formula maps that to 85 years, which is old, but not extraordinarily so.

Actually I think I agree with your assessment more. None of the age alignments really make a whole lot of sense to me, even for bigger breeds of dogs. Also, I feel like I've noticed adolescent and mischevious behavior in some of our dogs well into the 2-3 age range on occasion

This behavior mainly noted for cocker spaniels and Korean jindos

Giant breeds mature much more slowly, taking two to three years to be fully grown, and effectively age faster after they reach that point, to the extent that they'd be considered elderly by eight or nine years. The 16ln(x)+31 formula already overestimates the effective age of young dogs and underestimates for old dogs; taking giant breeds into consideration just makes its failures even worse.

Right? My yellow labrador is pushing 11 and he's all but indistinguishable from his 2-year-old self, aside from a relatively minor decline in energy.

We call him the Eternal Puppy. We expected aging was going to catch up by now. Still very little sign that it's happening.

If I had that dog's energy, I would never be out of shape.

Umm...doesn't the formula imply that the dog age starts at 31?

That makes no sense either. My 1 year old dog is definitely not a 31 year old adult as far as behavior goes (incidentally, I am myself ~31,).

I'd put 1 year approximately equivalent to a teenager, depending on the size of the breed (12 year old for larger breeds, late teens for small breeds)

Not quite. Ages are usually counted from 0. ln(0) is undefined, but after that from the first moment after birth until some time in its 52nd day, a dog's age is negative in dog-time (that's probably why it's considered important for the puppy to remain with its parents during this period; a negative-aged dog on its own is like a naked singularity). Then from day 52 to the end of its first year, the dog will age from 0 to 31.

The other end of the scale is surprising too: 200 human years is less than 116 dog years.

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