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Tuesday, November 10, 2026Nov 10

Think 1 dog year equals 7 people years? Not so fast…

This composite of 10 photographs shows Oscar, a wire-haired dachshund from 8 weeks old, top left, to 10 years old, bottom right. Photos by year are from top left; 2007, 2008, 2009, 2010, 2011 and from bottom left; 2012, 2013, 2014, 2015 and 2016. (AP Photo/Benny Snyder)
This composite of 10 photographs shows Oscar, a wire-haired dachshund from 8 weeks old, top left, to 10 years old, bottom right. Photos by year are from top left; 2007, 2008, 2009, 2010, 2011 and from bottom left; 2012, 2013, 2014, 2015 and 2016. (AP Photo/Benny Snyder) This composite of 10 photographs shows Oscar, a wire-haired dachshund from 8 weeks old, top left, to 10 years old, bottom right. Photos by year are from top left; 2007, 2008, 2009, 2010, 2011 and from bottom left; 2012, 2013, 2014, 2015 and 2016. (AP Photo/Benny Snyder)
photo Lilly the pug stands by her birthday cake on her 14th birthday. Dogs of different sizes age at different rates, with small dogs living longer and entering their senior years later.

Everyone says it: One year for a dog equals seven years for a human. But like a lot of things everyone says, it’s wrong.

Dogs do have life stages a lot like humans’, but the math isn’t that straightforward. To start, a 1-year-old dog isn’t equivalent to a 7-year-old human.

“If you look at a 1-year-old dog, he’s sexually mature,” says veterinarian Dr. Marty Becker. “They still have a little filling out to do and they’re not completely mentally mature, but they’re full adult size and capable of reproducing.”

Veterinary behaviorist Dr. Lisa Radosta suggests thinking of a 1-year-old dog as roughly mentally equivalent to a 13-year-old human. This means that a lot of development is packed into your puppy’s first year.

“If I keep my human baby home for the first year of her life, it doesn’t matter. I have a lot of time before she gets to kindergarten age at 5,” Radosta says. “But if you wait with a dog, you now have a teenager on your hands – a teenager who’s never seen a UPS truck, never seen a man in a hat, never seen a dog who barks at him.”