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

About 15: a one-year-old cat is sexually mature and nearly full grown, like a mid-teenager. At 6 months it is about 8, at 2 years 24. After that the pace drops to 4 human years per cat year.

When is a cat a senior?

International Cat Care's stages: kitten to 1 year, junior 1-2, prime 3-6, mature 7-10, senior 11-14 (60-72 in human terms), super senior from 15 (76+). Vets usually recommend twice-yearly checks from the mature stage, when kidney and thyroid problems start to appear.

Is it the same for dogs?

The AKC dog rule starts the same (15, then 24 at two) but then adds 5 a year instead of 4, and big dogs age faster still: a 10-year-old cat is 56 where a 10-year-old medium dog is 64. The dog age guide has the year-by-year dog table and the epigenetic clock.

Do indoor cats age slower?

The count in human years is the same; what changes is life expectancy. Indoor cats commonly live well into their late teens, outdoor cats considerably less on average because of traffic, fights and infections. Weight, dental care and vaccination matter more than the formula.

How does age change feeding?

Kittens are fed per kilogram by age (up to 218 kcal/kg under 8 weeks), adults by the NRC equations, and many cats over 11 need more calories, not fewer, as digestion becomes less efficient. Weigh a senior cat monthly; unplanned weight loss is the most common early sign of illness.

How old is my cat in human years? Table from 1 to 20

A 5-year-old cat is about 36 in human years, a 10-year-old about 56, a 15-year-old 76 and a 20-year-old 96. The convention used by International Cat Care and most vets counts the first year as 15 human years, the second as 9 more, then 4 a year; cats mature fast and age slowly afterwards, so the old times-seven rule is wrong at both ends. The table below runs from 1 to 20 with the life stage for each year.

Open the pet age calculator

Cat years to human years, 1 to 20

Cat age in human years with the International Cat Care life stage
Cat years	Human years	Life stage
1	15	junior
2	24	junior
3	28	prime
4	32	prime
5	36	prime
6	40	prime
7	44	mature
8	48	mature
9	52	mature
10	56	mature
11	60	senior
12	64	senior
13	68	senior
14	72	senior
15	76	super senior
16	80	super senior
17	84	super senior
18	88	super senior
19	92	super senior
20	96	super senior

Kittens, by month

The first year counts 15 human years spread evenly across the months.

Kitten age in human years
Kitten age	Human years
3 months	4
6 months	8
9 months	11
12 months	15

Cat, dog and the times-seven rule

The same age under the three rules
Years	Cat	Dog (AKC rule)	Times seven
1	15	15	7
2	24	24	14
5	36	39	35
10	56	64	70
15	76	89	105

Enter any age, including months, in the pet age calculator to see the cat convention and both dog rules side by side.

Frequently asked questions

How old is a 1-year-old cat in human years?: About 15: a one-year-old cat is sexually mature and nearly full grown, like a mid-teenager. At 6 months it is about 8, at 2 years 24. After that the pace drops to 4 human years per cat year.
When is a cat a senior?: International Cat Care's stages: kitten to 1 year, junior 1-2, prime 3-6, mature 7-10, senior 11-14 (60-72 in human terms), super senior from 15 (76+). Vets usually recommend twice-yearly checks from the mature stage, when kidney and thyroid problems start to appear.
Is it the same for dogs?: The AKC dog rule starts the same (15, then 24 at two) but then adds 5 a year instead of 4, and big dogs age faster still: a 10-year-old cat is 56 where a 10-year-old medium dog is 64. The dog age guide has the year-by-year dog table and the epigenetic clock.
Do indoor cats age slower?: The count in human years is the same; what changes is life expectancy. Indoor cats commonly live well into their late teens, outdoor cats considerably less on average because of traffic, fights and infections. Weight, dental care and vaccination matter more than the formula.
How does age change feeding?: Kittens are fed per kilogram by age (up to 218 kcal/kg under 8 weeks), adults by the NRC equations, and many cats over 11 need more calories, not fewer, as digestion becomes less efficient. Weigh a senior cat monthly; unplanned weight loss is the most common early sign of illness.

How old is my dog in human years? Table from 1 to 16
Year-by-year table of dog age in human years by the AKC rule and the epigenetic clock, when a dog is senior by size, and the International Cat Care cat table.
Dog age chart by size: small, medium, large and giant dogs
The AKC chart of dog years to human years for small, medium, large and giant dogs, years 1 to 16, next to the 15/9/5 rule, weight cut-offs and when each size is senior.
How many cups of dog food per day?
Cups of kibble a day by dog weight from the calories on your bag: tables for 300 to 450 kcal per cup, inactive and active adults, and meals.
How much should I feed my dog? Grams and cups by weight
Daily calories and grams of dry food for dogs from 2 to 50 kg, inactive and active, on foods from 3,400 to 4,000 kcal/kg, with the WSAVA chart range.

Sources

NRC 2006, Nutrient Requirements of Dogs and Cats — adult, puppy and kitten energy equations
WSAVA, Calorie Needs for Healthy Adult Dogs (July 2020) — chart range for dogs
WSAVA, Calorie Needs for Healthy Adult Cats (July 2020) — chart range for cats
AAHA 2021 Nutrition and Weight Management Guidelines — weight loss at the resting requirement of the target weight

Published 2026-09-17, last updated 2026-09-17. Figures are starting points from the published equations: individual animals vary by up to 30%, so adjust by body condition and ask your vet for puppies under 8 weeks, pregnancy, lactation or any illness.