Cat Age Calculator
Convert cat age and human age in both directions and see the corresponding life stage.
Did You Know?
Larger dogs age faster than smaller ones. A Great Dane is considered senior at 5-6 years!
Enter Details
Fill in your dog's information
Weight sets the size group: under 10 kg, 10-25 kg, or over 25 kg.
Small: <10kg | Medium: 10-25kg | Large: >25kg
Ready to Calculate?
Enter your dog's years and months to see the equivalent human age.
Use this chart as a quick reference after the calculator. Small, medium, and large dogs age similarly during the first two years, then larger dogs tend to move through life stages faster.
| Dog age | Small dog | Medium dog | Large dog |
|---|---|---|---|
| 1 month | 1 year | 1 year | 1 year |
| 3 months | 4 years | 4 years | 4 years |
| 6 months | 8 years | 8 years | 8 years |
| 1 year | 15 years | 15 years | 15 years |
| 2 years | 24 years | 24 years | 24 years |
| 3 years | 28 years | 29 years | 30 years |
| 4 years | 32 years | 34 years | 36 years |
| 5 years | 36 years | 39 years | 42 years |
| 6 years | 40 years | 44 years | 48 years |
| 7 years | 44 years | 49 years | 54 years |
| 8 years | 48 years | 54 years | 60 years |
| 9 years | 52 years | 59 years | 66 years |
| 10 years | 56 years | 64 years | 72 years |
| 11 years | 60 years | 69 years | 78 years |
| 12 years | 64 years | 74 years | 84 years |
| 13 years | 68 years | 79 years | 90 years |
| 14 years | 72 years | 84 years | 96 years |
| 15 years | 76 years | 89 years | 102 years |
The old "1 dog year = 7 human years" rule is too simple. Dogs age quickly during the first two years, then their aging rate changes by body size. This calculator combines age, breed size, and life stage to give a more useful estimate.
Method note: this calculator uses a size-adjusted dog age model: the first dog year is about 15 human years, the second brings most dogs to about 24 human years, and later years vary by body size. Life-stage guidance is aligned with the 2019 AAHA Canine Life Stage Guidelines. Read the AAHA canine life-stage guidelines.
Breed does not change age by itself; breed mostly matters because it usually predicts adult body size and typical lifespan. That is why the calculator lets you choose a breed or manually select small, medium, or large.
Under 10kg. Live longest (14-16 years average). Age slowest after maturity.
10-25kg. Average lifespan of 10-14 years. Balanced aging rate.
Over 25kg. Shorter lifespans (8-12 years). Age faster in later years.
A 7-year-old toy breed and a 7-year-old giant breed should not be treated as the same life stage. Larger dogs often need senior-care conversations earlier, while smaller dogs may stay in mature-adult routines for longer.
| Stage | Human Age Equivalent | What to Expect |
|---|---|---|
| Puppy | 0-6 human years | Rapid growth, learning, high energy |
| Junior | 6-15 human years | Adolescence, training important |
| Adult | 15-40 human years | Prime years, stable energy |
| Mature | 40-60 human years | Slowing down, health monitoring |
| Senior | 60-80 human years | More rest needed, gentle exercise |
| Geriatric | 80+ human years | Comfort priority, quality time |
The age result is most useful when it changes the next step: care routines, senior planning, birthday captions, or a shareable dog profile moment.
Use the result for a birthday portrait, adoption day card, or profile update.
Large senior dogs may need mobility support earlier, while small dogs may need long-term dental and weight routines.
Turn the age, breed, and personality context into a portrait or ID-style image.
Continue with a relevant free utility or move into a pet photo creation task.