Dog years to human years calculator

Bigger dogs age faster, so the result depends on size. Enter your dog's age and pick a size to see the human-year equivalent.

Your dog is about

46human years

Size-based chart, medium dog

Research formula (2020): 62

The research formula applies from about one year of age and was built from Labrador retrievers, so it is a rough comparison for other breeds.

Dog age chart by size

Dog age (years)	Small	Medium	Large	Giant	Research formula
1	15	15	15	15	31
2	24	24	24	24	42
3	28	28	29	30	49
4	32	33	35	36	53
5	36	37	40	42	57
6	40	42	45	49	60
7	44	46	50	56	62
8	48	51	56	64	64
9	52	55	61	71	66
10	56	60	66	78	68
11	60	65	71	85	69
12	64	69	77	93	71
13	68	74	82	100	72
14	72	78	88	108	73
15	76	83	93	115	74
16	80	88	98	122	75

Human years. The size columns follow the AAHA reference points at ages 1, 2, 5, 10 and 15, with the years in between estimated in a straight line.

Why "multiply by 7" is out of date

The old rule says one dog year equals seven human years. Veterinary charts do not work that way. Dogs reach the equivalent of a teenager in their first year, about 15 human years, and are around 24 by age two. After that the pace depends on size: giant dogs age fastest, small dogs slowest.

In 2020 a team at the University of California San Diego compared chemical changes in the DNA of 104 Labrador retrievers with those of humans. Their formula is human age = 16 × ln(dog age) + 31. Depending on size and age it can come out higher or lower than the size chart, so the two methods can differ by a lot. We show both so you can compare.

Look up a specific age

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Questions

Which result should I trust?

Neither is exact. The size chart is the more common veterinary reference. The research formula is newer but comes from one breed. Use them as a range, not a diagnosis.

What size is my dog?

Use the adult weight. Under 20 lb is small, 21 to 50 lb is medium, 51 to 90 lb is large, and over 90 lb is giant. For mixed breeds, go by the weight your vet records.

How old is a 10 year old dog?

Between about 56 and 78 human years by the size chart, from small to giant. A senior dog usually benefits from more frequent vet visits.

What about cats?

Cats follow one simple rule, see the cat years to human years calculator.

How old am I in dog years?

Try the human years to dog years calculator.

Sources

American Animal Hospital Association (AAHA), canine and feline age chart, human-year equivalents by dog size.
Wang T. et al., "Quantitative Translation of Dog-to-Human Aging by Conserved Remodeling of the DNA Methylome", Cell Systems, 2020 (University of California San Diego).
American Veterinary Medical Association (AVMA), general guidance on a dog's first two years (15 and 9 human years).

Last reviewed 2026-10-26.

Dog age (years)	Small	Medium	Large	Giant	Research formula
1	15	15	15	15	31
2	24	24	24	24	42
3	28	28	29	30	49
4	32	33	35	36	53
5	36	37	40	42	57
6	40	42	45	49	60
7	44	46	50	56	62
8	48	51	56	64	64
9	52	55	61	71	66
10	56	60	66	78	68
11	60	65	71	85	69
12	64	69	77	93	71
13	68	74	82	100	72
14	72	78	88	108	73
15	76	83	93	115	74
16	80	88	98	122	75

Dog age (years)	Small	Medium	Large	Giant	Research formula
1	15	15	15	15	31
2	24	24	24	24	42
3	28	28	29	30	49
4	32	33	35	36	53
5	36	37	40	42	57
6	40	42	45	49	60
7	44	46	50	56	62
8	48	51	56	64	64
9	52	55	61	71	66
10	56	60	66	78	68
11	60	65	71	85	69
12	64	69	77	93	71
13	68	74	82	100	72
14	72	78	88	108	73
15	76	83	93	115	74
16	80	88	98	122	75

Dog age (years)	Small	Medium	Large	Giant	Research formula
1	15	15	15	15	31
2	24	24	24	24	42
3	28	28	29	30	49
4	32	33	35	36	53
5	36	37	40	42	57
6	40	42	45	49	60
7	44	46	50	56	62
8	48	51	56	64	64
9	52	55	61	71	66
10	56	60	66	78	68
11	60	65	71	85	69
12	64	69	77	93	71
13	68	74	82	100	72
14	72	78	88	108	73
15	76	83	93	115	74
16	80	88	98	122	75