How old is a 3-month-old dog in human years?

A 3-month-old puppy is about

in human years

PuppyUnder 1 year

Growing fast and learning everything. Needs puppy food, vaccinations, and early training.

What 3 months means for a puppy

The first year of a dog's life counts as about 15 human years for every size, so each month adds about 1.25. Size only starts to matter after the second year. A puppy aged 3 months is still in the puppy stage. Growing fast and learning everything. Needs puppy food, vaccinations, and early training.

Care notes for puppies

Follow your vet's vaccination and worming schedule.
Feed a puppy formula. Large breeds often need one made for large-breed puppies.
Socialisation and basic training now pay off for life.

Puppy age chart

Puppy's age	Human years
1 month	1
2 months	3
3 months	4
4 months	5
5 months	6
6 months	8
7 months	9
8 months	10
9 months	11
10 months	13
11 months	14
1 year	15

Check any other age

Dog size

Dog’s age in years

Plus months

Common questions

Does size matter for a 3-month-old puppy?

Not for the human age. Every size counts the first year as about 15 human years. Size matters from the second year on.

How old is a 1-year-old dog in human years?

About 15 for every size. The second year adds about 9 more, so a 2-year-old dog is around 24.

Keep going

See the full dog years to human years chart or the equivalent for a 3-month-old cat.