Quick conversion

Dog Years to Human Years: The Conversion Chart

Look up a dog's human-year equivalent by size, then use the calculator for ages that fall between whole years. The chart keeps the most common comparisons in one place.

The first two calendar years account for most of a dog's early development. After that, the yearly step depends on whether the dog is small, medium, large or giant.

Your dog's size

Years0 to 30Months0 to 11

In human years

39human years

Life stage: adult

Maintenance years: steady weight and activity matter more than milestones.

For comparison, the epigenetic clock from Wang et al. (2020) puts a medium dog of this age at about 56.8 human years. Different published models disagree; see how the math works.

Dog years chart

Dog years to human years by size

Use the table for a fast lookup. Values are rounded to whole human years and show why a single multiplier cannot describe every dog.

Dog age (years)	Small up to 20 lb	Medium 21-50 lb	Large 51-100 lb	Giant over 100 lb
1	15	15	14	12
2	24	24	24	22
3	28	29	30	29
4	32	34	36	36
5	36	39	42	43
6	40	44	48	50
7	44	49	54	57
8	48	54	60	64
9	52	59	66	71
10	56	64	72	78
11	60	69	78	85
12	64	74	84	92
13	68	79	90	99
14	72	84	96	106
15	76	89	102	113
16	80	94	108	120

Human-year equivalents by size class, rounded to whole years. Model follows AVMA guidance with AKC size adjustment; different published models give different numbers, and that is expected.

How to use the chart

Three rules explain most dog years conversions

Year one is fast

A one-year-old dog is already around 12 to 15 human years, depending on size. That is why multiplying the calendar age by seven misses puppy development.

Year two reaches adulthood

By the second birthday, the chart lands around 22 to 24 human years. The calculator scales the months between the two anchor points.

Size sets the later pace

After year two, each calendar year adds about 4 human years for a small dog and up to 7 for a giant dog in this model.

Published models can disagree at the edges. For the background behind these numbers, read the full explanation of the dog age in human years model.

Worked dog years to human years examples

Calendar age	Small	Medium	Large	Giant	What it shows
1 yearFirst birthday	15	15	14	12	Early development is already far beyond seven human years.
2 yearsSecond birthday	24	24	24	22	Most size columns are close to the mid-twenties.
5 yearsAdult dog	36	39	42	43	Size begins to create a clear gap between the columns.
10 yearsSenior dog	56	64	72	78	The same calendar age maps to different life stages.

Questions

Dog years to human years FAQ

How many human years is one dog year?

On the size-adjusted model, one calendar year is about 15 human years for small and medium dogs, 14 for large dogs and 12 for giant dogs. It is not a fixed seven-year conversion.

How many human years is a 2-year-old dog?

A 2-year-old dog is about 24 human years on the small, medium and large columns, and about 22 for a giant dog. After the second year, size changes the rate more clearly.

Why does dog size change the conversion?

Large and giant dogs tend to move through later life stages faster than small dogs. The chart therefore uses different yearly increments after the first two calendar years.

Is this dog years chart medically accurate?

It is an educational estimate based on published size-adjusted guidance. Breed, health, lifestyle and the model selected can change the result, so it should not replace veterinary advice.

Sources for the conversion chart

This page uses a size-adjusted educational model. These references explain the underlying age guidance and why different published models can produce different answers.

Choose the next step

Use the dog age calculator for a live result, read the full conversion explanation for the model details, or estimate an age without a birthday.

Dog age (years)	Small up to 20 lb	Medium 21-50 lb	Large 51-100 lb	Giant over 100 lb
1	15	15	14	12
2	24	24	24	22
3	28	29	30	29
4	32	34	36	36
5	36	39	42	43
6	40	44	48	50
7	44	49	54	57
8	48	54	60	64
9	52	59	66	71
10	56	64	72	78
11	60	69	78	85
12	64	74	84	92
13	68	79	90	99
14	72	84	96	106
15	76	89	102	113
16	80	94	108	120

Dog age (years)	Small up to 20 lb	Medium 21-50 lb	Large 51-100 lb	Giant over 100 lb
1	15	15	14	12
2	24	24	24	22
3	28	29	30	29
4	32	34	36	36
5	36	39	42	43
6	40	44	48	50
7	44	49	54	57
8	48	54	60	64
9	52	59	66	71
10	56	64	72	78
11	60	69	78	85
12	64	74	84	92
13	68	79	90	99
14	72	84	96	106
15	76	89	102	113
16	80	94	108	120

Dog age (years)	Small up to 20 lb	Medium 21-50 lb	Large 51-100 lb	Giant over 100 lb
1	15	15	14	12
2	24	24	24	22
3	28	29	30	29
4	32	34	36	36
5	36	39	42	43
6	40	44	48	50
7	44	49	54	57
8	48	54	60	64
9	52	59	66	71
10	56	64	72	78
11	60	69	78	85
12	64	74	84	92
13	68	79	90	99
14	72	84	96	106
15	76	89	102	113
16	80	94	108	120