Dog Age Calculator | Dog Years to Human Years Chart

Dog age calculator converts dog years to human years using both the AVMA rule of thumb and the 2020 epigenetic formula, with life stage by breed size. Free, no signup. Designed specifically for developers and professionals, this free online calculator runs entirely in your browser to process tasks quickly and securely. Enjoy unlimited usage with no data tracking and no registration required.

Also known as: dog age calculator · dog years to human years · how old is my dog in human years · dog age chart by size · when is a dog a senior · pet age calculator

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Your Dog

Age in years. Decimals are fine, so a 9 month old puppy is 0.75.

Age in years

Adult size

Dog Years to Human Years

Both methods side by side, so you can see where they part company.

Dog age	AVMA rule	Epigenetic formula
1	15	31
2	24	42
3	29	49
4	34	53
5	39	57
7	49	62
10	64	68
13	79	72
16	94	75
20	114	79

How the AVMA Rule Works

The arithmetic behind the number, so you can check it on paper.

First year

+15

Puppy to young adult in twelve months.

Second year

Running total of 24 at age two.

Every year after

Flat, for the rest of the dog's life.

human years = 15 + 9 + 5 x (dog age - 2)

7 years old: 15 + 9 + 5 x 5 = 49 human years (example)

This is the rule of thumb the American Veterinary Medical Association gives pet owners, and the one the American Kennel Club repeats: about 15 human years for a dog's first year, about 9 more for the second, then roughly 5 for each year after that. It replaced the old "multiply by 7" shortcut, which was never based on anything and badly undercounts puppies.

The reason it is front-loaded is that dogs finish growing far sooner than we do. A one year old dog is sexually mature, done growing, and socially adult. Nothing a human does at 15 is comparable to what a human does at 1, which is exactly the point of the conversion. Once a dog is grown, the pace settles into something close to linear, and 5 human years per dog year is the working estimate for that stretch.

For a dog under a year old this calculator prorates the 15, so a 9 month old comes out at about 11. The AVMA guidance does not spell that out, but it is the only reading of "the first year is worth 15" that stays consistent at the 12 month mark.

Treat the output as a conversation piece, not a medical figure. It carries no information about your specific dog's health, and a vet assesses aging from bloodwork, dentition, joints and body condition rather than from a multiplier.

Dog Age Chart by Breed Size

Human equivalents by adult weight, from the AAHA Canine Life Stage Guidelines age chart.

Dog age	Small20 lb and under	Medium21 to 50 lb	Large51 to 90 lb	Giantover 90 lb
1	15	15	15	15
2	24	24	24	24
3	28	28	30	32
4	32	33	35	37
5	36	37	40	42
6	40	42	45	49
7	44	47	50	56
8	48	51	55	64
9	52	56	61	71
10	56	60	66	78
11	60	65	72	86
12	64	69	77	93
13	68	74	82	101
14	72	78	88	108
15	76	83	93	115
16	80	87	99	123

This is the chart most sites label "the AVMA dog age chart", and the label is wrong. The AVMA publishes the 15 / 9 / 5 rule above, which has no size term in it. The size-by-size numbers here come from the AAHA Canine Life Stage Guidelines age poster, which in turn credits Appendix B of the Dog Owner's Home Veterinary Handbook, 4th edition. It is a lookup table someone compiled, not a formula fitted to data, which is worth knowing before you quote a single year of it back to your vet.

The two agree exactly for the first two years, at 15 and 24, and then fan out. By 10 a small dog reads 56 and a giant breed reads 78. By 16 the gap is 80 against 123. That spread is the chart's whole argument: large breeds live shorter lives, so the same calendar year costs them more. The giant column stops at 16 because the source leaves it blank past that point, which is its own kind of honesty about how few dogs over 90 pounds get there.

Where this chart matters in practice is screening, not trivia. A 6 year old Great Dane sitting at 49 in human terms is why vets move large breeds onto senior bloodwork years earlier than a Chihuahua of the same age.

About Dog Age Calculator

Convert your dog's age into human years using both the AVMA rule of thumb and the 2020 epigenetic formula, with life stage and senior onset by breed size.

Key Features

Two published methods side by side rather than one number presented as fact
The AVMA rule of thumb: 15 human years for the first year, 9 for the second, about 5 for each year after
The full arithmetic shown step by step, with a worked example that follows the age you entered
The 2020 epigenetic formula, 16 x ln(age) + 31, derived from DNA methylation in Labrador Retrievers
A complete dog age chart by breed size, ages 1 to 16, from the AAHA Canine Life Stage Guidelines
Life stage and senior onset adjusted by adult size, which is the part breed genuinely changes
Runs entirely in your browser with no signup and nothing uploaded

Use Cases

Working out roughly how old your dog is in human terms
Looking up a small, medium, large or giant breed in a dog years chart by weight
Checking whether your dog has reached the age where vets recommend senior screening
Understanding why two dog age calculators give you different answers
Comparing the old rule of thumb against the newer methylation research
Explaining to a child how quickly a puppy grows up compared to a person

Related Keywords

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dog years to human years

how old is my dog in human years

avma dog age chart

dog age chart by size

dog years chart by weight

puppy age in human years

when is a dog a senior

dog age conversion formula

epigenetic dog age calculator

Privacy & Security

All processing happens locally in your browser. Your data never leaves your computer, ensuring complete privacy and security.

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Frequently asked questions

What is Dog Age Calculator used for?

Dog age calculator converts dog years to human years using both the AVMA rule of thumb and the 2020 epigenetic formula, with life stage by breed size. Free, no signup.

Is Dog Age Calculator free to use?

Yes. Dog Age Calculator is completely free with no usage limits, and there is no paid tier required to use it.

Do I need an account to use Dog Age Calculator?

No. Dog Age Calculator works immediately in your browser with no signup, login, or email address required.

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Dog age	Small20 lb and under	Medium21 to 50 lb	Large51 to 90 lb	Giantover 90 lb
1	15	15	15	15
2	24	24	24	24
3	28	28	30	32
4	32	33	35	37
5	36	37	40	42
6	40	42	45	49
7	44	47	50	56
8	48	51	55	64
9	52	56	61	71
10	56	60	66	78
11	60	65	72	86
12	64	69	77	93
13	68	74	82	101
14	72	78	88	108
15	76	83	93	115
16	80	87	99	123

Dog age	Small20 lb and under	Medium21 to 50 lb	Large51 to 90 lb	Giantover 90 lb
1	15	15	15	15
2	24	24	24	24
3	28	28	30	32
4	32	33	35	37
5	36	37	40	42
6	40	42	45	49
7	44	47	50	56
8	48	51	55	64
9	52	56	61	71
10	56	60	66	78
11	60	65	72	86
12	64	69	77	93
13	68	74	82	101
14	72	78	88	108
15	76	83	93	115
16	80	87	99	123

Dog age	Small20 lb and under	Medium21 to 50 lb	Large51 to 90 lb	Giantover 90 lb
1	15	15	15	15
2	24	24	24	24
3	28	28	30	32
4	32	33	35	37
5	36	37	40	42
6	40	42	45	49
7	44	47	50	56
8	48	51	55	64
9	52	56	61	71
10	56	60	66	78
11	60	65	72	86
12	64	69	77	93
13	68	74	82	101
14	72	78	88	108
15	76	83	93	115
16	80	87	99	123

Dog age	Small20 lb and under	Medium21 to 50 lb	Large51 to 90 lb	Giantover 90 lb
1	15	15	15	15
2	24	24	24	24
3	28	28	30	32
4	32	33	35	37
5	36	37	40	42
6	40	42	45	49
7	44	47	50	56
8	48	51	55	64
9	52	56	61	71
10	56	60	66	78
11	60	65	72	86
12	64	69	77	93
13	68	74	82	101
14	72	78	88	108
15	76	83	93	115
16	80	87	99	123

Dog age	Small20 lb and under	Medium21 to 50 lb	Large51 to 90 lb	Giantover 90 lb
1	15	15	15	15
2	24	24	24	24
3	28	28	30	32
4	32	33	35	37
5	36	37	40	42
6	40	42	45	49
7	44	47	50	56
8	48	51	55	64
9	52	56	61	71
10	56	60	66	78
11	60	65	72	86
12	64	69	77	93
13	68	74	82	101
14	72	78	88	108
15	76	83	93	115
16	80	87	99	123

Dog age	Small20 lb and under	Medium21 to 50 lb	Large51 to 90 lb	Giantover 90 lb
1	15	15	15	15
2	24	24	24	24
3	28	28	30	32
4	32	33	35	37
5	36	37	40	42
6	40	42	45	49
7	44	47	50	56
8	48	51	55	64
9	52	56	61	71
10	56	60	66	78
11	60	65	72	86
12	64	69	77	93
13	68	74	82	101
14	72	78	88	108
15	76	83	93	115
16	80	87	99	123