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How old is my dog in human years?

A dog's first year equals about 15 human years, the second year about 9 more, and each year after that about 5, according to the AVMA rule of thumb. So a 10-year-old dog is roughly 64 in human years. Size changes when old age starts: giant dogs are seniors at about 6 to 7 years, small dogs at about 8 to 11.

When is a dog a senior?

• Small dogs (under 20 lb): about 8 to 11 years
• Medium dogs (20-50 lb): about 8 to 10 years
• Large dogs (50-90 lb): about 8 to 9 years
• Giant dogs (over 90 lb): about 6 to 7 years

Dog years to human years chart

Dog age	Human years (rule of thumb)	DNA formula
1	15	31
2	24	42
3	29	49
4	34	53
5	39	57
6	44	60
7	49	62
8	54	64
9	59	66
10	64	68
11	69	69
12	74	71
13	79	72
14	84	73
15	89	74
16	94	75
17	99	76
18	104	77
19	109	78
20	114	79

Frequently asked questions

How old is my dog in human years?

By the AVMA rule of thumb, year one is about 15 human years, year two adds about 9 (24 total), and each year after adds about 5. A 7-year-old dog is about 49, a 10-year-old about 64 and a 14-year-old about 84 in human years.

Is one dog year really seven human years?

No. Dogs mature much faster in their first two years. A 1-year-old dog is already closer to a young adult than to a 7-year-old child, which is why the first year counts as about 15 human years.

When is a dog considered a senior?

The AVMA defines a senior dog as one in the last 25% of the expected life span for its breed. On average that is about 8-11 years for small dogs (under 20 lb), 8-10 for medium dogs (20-50 lb), 8-9 for large dogs (50-90 lb) and 6-7 for giant dogs (over 90 lb).

What is the DNA formula for dog age?

A 2020 UC San Diego study of more than 100 Labrador retrievers, published in Cell Systems, compared DNA aging marks in dogs and people. Its formula is human age = 16 x ln(dog age) + 31. It was built on Labradors, so treat it as a rough comparison for other breeds.

Related care guides

• Signs your dog is aging
• Preparing for a senior vet visit

More free senior dog tools

• Weight and calorie calculator: Normal weight by breed and age, ideal weight, daily calories and a safe weight-loss pace.
• Water intake calculator: How much your senior dog should drink a day, and when it is too much.
• Sleeping breathing rate counter: Tap along while your dog sleeps to get breaths per minute and see if it is in the usual range.
• Bladder infection (UTI) symptoms: Straining, frequent peeing, blood or smell: what fits a UTI and when it is an emergency.
• Leaking urine? Incontinence check: Sort leaking from infection, thirst, memory or mobility problems, with next steps.
• Is my dog overweight? Body check: Three quick hands-on checks to estimate the body condition score.
• Dog dementia (CCD) checklist: Confusion, night pacing, accidents and memory changes in older dogs.
• Arthritis and pain checklist: Everyday signs that an older dog is sore, and what helps at home.
• Quality of life scale: is it time?: Score 7 areas of daily life, track good and bad days, and know when to talk to your vet about euthanasia.
• Printable weekly health tracker: Log weight, appetite, water, sleep and accidents for your vet. No sign-up.

Sources: AKC: How to calculate dog years to human years · AVMA: Senior pets · NPR/KUNC: New formula for a dog's age in human years (UC San Diego study, Cell Systems 2020)

Educational only. Not a substitute for your veterinarian. Updated October 2026. SILVERPAW is operated by ILYESHOPI LLC.