Dog years to human years chart

On the AVMA chart for a medium-size dog, 1 dog year is 15 human years, 2 is 24, 7 is 47 and 16 is 87. The 2020 DNA-clock formula reads higher up to 12 years and lower after. Pick an age for the full answer.

Dog age in human years, 1 to 20

AVMA values are for a medium-size dog of 21 to 50 lb. DNA-clock values are 16 × ln(age) + 31, rounded.

Dog ageAVMA chart (medium)DNA clockTimes 7
1 year15317
2 years244214
3 years284921
4 years325328
5 years365735
6 years426042
7 years476249
8 years516456
9 years566663
10 years606870
11 years656977
12 years697184
13 years747291
14 years787398
15 years8374105
16 years8775112
17 years—76119
18 years—77126
19 years—78133
20 years—79140

The AVMA chart has no rows past 16 years, and the oldest dog in the DNA study was 16, so the clock values for 17 to 20 go beyond its data.

Life stage by size

Stages from the 2019 AAHA guidelines; senior ages by size from AVMA.

Dog ageSmall or toyless than 20 lbMedium20 to 50 lbLarge50 to 90 lbGiantmore than 90 lb
1 yearYoung adultYoung adultYoung adultYoung adult
2 yearsYoung adultYoung adultYoung adultYoung adult
3 yearsYoung adult or matureYoung adult or matureYoung adult or matureYoung adult or mature
4 yearsMatureMatureMatureMature
5 yearsMatureMatureMatureMature
6 yearsMatureMatureMatureMature or senior
7 yearsMatureMatureMatureSenior
8 yearsMature or seniorMature or seniorMature or seniorSenior
9 yearsMature or seniorMature or seniorSeniorSenior
10 yearsMature or seniorSeniorSeniorSenior
11 yearsSeniorSeniorSeniorSenior
12 yearsSeniorSeniorSeniorSenior
13 yearsSeniorSeniorSeniorSenior
14 yearsSeniorSeniorSeniorSenior
15 yearsSeniorSeniorSeniorSenior
16 yearsSeniorSeniorSeniorSenior
17 yearsSeniorSeniorSeniorSenior
18 yearsSeniorSeniorSeniorSenior
19 yearsSeniorSeniorSeniorSenior
20 yearsSeniorSeniorSeniorSenior

“Mature or senior” means the dog is inside AVMA’s senior-age window for its size: for example, 8 to 11 years for small dogs. “Young adult or mature” covers 3 to 4 years, when AAHA says most dogs finish maturing. These are averages: AVMA ties the senior years to the expected lifespan of each breed.

Puppies under a year

The AVMA chart starts at 1 year, so these come from the DNA-clock formula alone.

Puppy ageDNA clock
2 months2
3 months9
4 months13
6 months20
9 months26

The study matched about 8 weeks in a dog with about 9 months in a baby, when the first teeth come in for both.

AVMA’s older size ranges

From AVMA’s 2010 senior-pets brochure, since replaced.

Dog ageSmall dog (to 20 lb)Very large (over 90 lb)
7 years4456
10 years5678
15 years76115
20 years96120

It gave only these four ages and only the two ends of the range. The year-by-year size charts on many pet sites don’t name a veterinary source, so this site doesn’t use them.

Sources

Every number on this page comes from these, checked October 2, 2026. Human-age equivalents are estimates, not veterinary advice.

  1. AVMA, “Pets age faster than people” (PDF). Dog column for a medium-size dog of 21 to 50 lb, ages 1 to 16; cat column, ages 1 to 16. AVMA adds that pet ages are approximate and that weight and breed may influence aging.
  2. AVMA, “Caring for senior cats and dogs.” Dog size groups by weight, the age each group becomes senior, cats senior after about 10, and the statement that dogs don’t age 7 human years per year.
  3. AVMA “Senior Pets” client brochure, revision 7/10, since replaced by a 2023 edition without the chart (archived copy). Human-age ranges from small to very large dogs at 7, 10, 15 and 20 years.
  4. Wang T, Ma J, Hogan AN, et al. “Quantitative Translation of Dog-to-Human Aging by Conserved Remodeling of the DNA Methylome.” Cell Systems 11 (2020). The formula human age = 16 ln(dog age) + 31, from 104 dogs, mostly Labrador retrievers, aged a few weeks to 16 years. See also the UC San Diego news release.
  5. UC Davis School of Veterinary Medicine, “Calculating your dog’s age.” Why the times-7 rule is inaccurate and where it likely came from.
  6. 2019 AAHA Canine Life Stage Guidelines (PDF). Puppy, young adult, mature adult, senior and end-of-life stages.

More age tools

Dog age calculatorYears and months, any size, both methods side by side. Cat years chartEvery cat age from 1 to 25 in human years.