Free Tool

Dog Years to Human Years Calculator

Find out how old your dog is in human years — by breed size.

How old is your dog in human years? It's not as simple as multiplying by 7. Enter your dog's age and size below to see where they really are in life, then check the full 1–20 year chart for every size.

Dog's age (years)

Breed size

Please enter a valid age between 0 and 30.

Life stage

Why You Can't Just Multiply by 7

The "multiply by 7" rule is a myth. Dogs age fast in their first two years — a one-year-old dog is roughly 15 in human years, and a two-year-old is about 24, matching the American Veterinary Medical Association's (AVMA) official conversion. After that, the AVMA cites a general rate of about 5 human years per dog year; we break that down further by size (small +4, medium +5, large +6) as a close approximation, since larger breeds are well known to age — and reach senior status — faster than small breeds.

Advanced: What the Science Says

In 2019, researchers at UC San Diego proposed a more precise formula based on changes in dog DNA methylation patterns: human age = 16 × ln(dog age) + 31. It tracked closely with the traditional milestones above for young dogs but curves differently with age. One caveat: the study was based on Labrador Retrievers, so it isn't necessarily generalizable across all breeds and sizes — which is why we use the size-based AVMA approach as our default calculator above.

Life Stages by Size

🐶 Puppy

Birth to 1 year old (all sizes). Focus on vaccinations, socialization and basic training.

🐕 Adult

From 1 year until the senior threshold for their size. Annual checkups and weight management matter most.

🦮 Senior

Small breeds ~10+, medium ~8–9+, large ~7+. Twice-yearly checkups and extra attention to joints and teeth.

Popular Breeds at a Glance

Here's what a 5-year-old dog looks like in human years across a few well-known breeds, using our size-based conversion:

Chihuahua (small)

At 5 years old, a Chihuahua is about 36 in human years — small breeds age more slowly once past puppyhood.

Beagle (medium)

At 5 years old, a Beagle is about 39 in human years.

Labrador Retriever (large)

At 5 years old, a Labrador is about 42 in human years — large breeds catch up and pass smaller ones by middle age.

Enter your own dog's breed size in the calculator above for a precise, age-specific result — or scroll down to the full chart below.

Full Dog Years to Human Years Chart (1–20)

Same age, different size, very different human-year equivalent — e.g. an 8-year-old small dog is around 48 in human years, while an 8-year-old large dog is closer to 60.

Dog Years	Small Breed	Medium Breed	Large Breed
1	15	15	15
2	24	24	24
3	28	29	30
4	32	34	36
5	36	39	42
6	40	44	48
7	44	49	54
8	48	54	60
9	52	59	66
10	56	64	72
11	60	69	78
12	64	74	84
13	68	79	90
14	72	84	96
15	76	89	102
16	80	94	108
17	84	99	114
18	88	104	120
19	92	109	126
20	96	114	132

Conversion figures are common industry estimates, not exact medical data. For a health assessment specific to your dog, consult your veterinarian.

Frequently Asked Questions

How old is my dog in human years?

It depends on size. The first year is worth about 15 human years and the second about 9 more (24 total) — this matches the AVMA's official conversion. After that, the AVMA cites roughly +5 human years per dog year as a general rule; we split that into small (+4), medium (+5) and large (+6) as a close approximation, since bigger dogs are known to age faster later in life.

Is 1 dog year really 7 human years?

No — the “multiply by 7” rule is a myth. Dogs mature much faster than that in their first two years, and the rate after that depends heavily on breed size, not a flat 7-to-1 ratio.

When is a dog considered senior?

Roughly age 10–11 for small breeds, around 8–9 for medium breeds, and as early as 7 for large breeds, since bigger dogs have shorter lifespans and age faster.

How old is a 10 year old dog?

Using our conversion: about 56 in human years for a small breed, 64 for a medium breed, and 72 for a large breed.

Dog Years	Small Breed	Medium Breed	Large Breed
1	15	15	15
2	24	24	24
3	28	29	30
4	32	34	36
5	36	39	42
6	40	44	48
7	44	49	54
8	48	54	60
9	52	59	66
10	56	64	72
11	60	69	78
12	64	74	84
13	68	79	90
14	72	84	96
15	76	89	102
16	80	94	108
17	84	99	114
18	88	104	120
19	92	109	126
20	96	114	132

Dog Years	Small Breed	Medium Breed	Large Breed
1	15	15	15
2	24	24	24
3	28	29	30
4	32	34	36
5	36	39	42
6	40	44	48
7	44	49	54
8	48	54	60
9	52	59	66
10	56	64	72
11	60	69	78
12	64	74	84
13	68	79	90
14	72	84	96
15	76	89	102
16	80	94	108
17	84	99	114
18	88	104	120
19	92	109	126
20	96	114	132