Find out how old your dog is in human years based on age and adult size. You’ll also see their approximate life stage and learn why different dogs age at different rates.
Results are general estimates and can vary by breed, genetics, lifestyle, and individual health.
Enter your dog's age and select their approximate adult size.
Size selected automatically from breed. You can still change it.
Dogs mature quickly during their first two years. After that, body size becomes increasingly important when estimating their equivalent human age.
A one-year-old dog is generally much closer developmentally to a human teenager than to a seven-year-old child. By age two, many dogs are comparable to young adults, and later aging varies more by size and breed.
| Dog Age | Small Dog | Medium Dog | Large Dog | Giant Dog |
|---|---|---|---|---|
| 1 year | 15 | 15 | 15 | 15 |
| 2 years | 24 | 24 | 24 | 24 |
| 3 years | 28 | 28 | 29 | 30 |
| 5 years | 36 | 37 | 40 | 42 |
| 7 years | 44 | 47 | 50 | 54 |
| 10 years | 56 | 60 | 66 | 72 |
| 12 years | 64 | 69 | 77 | 84 |
| 15 years | 76 | 83 | 94 | 102 |
Dog aging is not linear. Dogs mature rapidly early in life, then age at different rates depending partly on body size.
Use months for puppies or years for adult dogs.
Small, medium, large, and giant dogs tend to age differently later in life.
Get an estimated human-age equivalent and your dog's likely current life stage.
Small and large dogs may be the same chronological age but still be at different biological life stages. Smaller dogs generally have longer average lifespans, while large and giant breeds often enter their senior years earlier.
That’s why this calculator uses adult body size rather than applying one fixed formula to every dog.
The traditional seven-year rule is easy to remember, but it oversimplifies how dogs develop. Dogs mature much faster than humans during the first part of their lives. A one-year-old dog may already be physically and behaviorally closer to a human teenager than to a young child.
After the first two years, the difference between smaller and larger dogs becomes more noticeable. Genetics, breed, activity, nutrition, and overall health can also influence how an individual dog ages.
There isn’t one senior age that applies to every dog. Small dogs may not enter their senior years until around age 10 or later, while some large and giant breeds may be considered senior several years earlier.
Age-related changes can include shifts in activity, sleep, mobility, weight, appetite, recovery after exercise, or daily behavior. Regular veterinary checkups remain the best way to understand your individual dog’s changing needs.
Age is only one part of understanding your dog. Explore more guidance on aging, behavior, activity, and wellbeing through every stage of life.
Learn how size, breed, and individual development affect when dogs enter their senior years.
Read the guide →
Explore common changes in activity, sleep, mobility, and behavior as dogs move through later life stages.
Read the guide →
Learn why small dogs often live longer than large breeds and how body size can influence aging, lifespan, and senior life stages.
Read the guide →Explore more free tools and resources designed to help you better understand your dog’s breed, behavior, and everyday needs.
Explore dog breed traits and discover which breeds may suit different lifestyles.
Try the Dog Breed Quiz →Get dog name ideas based on style, personality, and inspiration.
Find a dog name →Explore practical guidance for building better habits and routines with your dog.
Explore dog training →Quick answers to common questions about dog years, human years, and canine life stages.
Enter your dog’s chronological age and approximate adult size. The calculator estimates a human-age equivalent based on faster development during the first two years and size-dependent aging later in life.
No. Dogs mature much more rapidly than humans during their early years, while later aging varies considerably by size, breed, genetics, lifestyle, and health.
A five-year-old dog may be roughly comparable to a human in their mid-to-late 30s or early 40s. Larger dogs generally receive a slightly higher human-age estimate than smaller dogs.
Depending on body size, a ten-year-old dog may be roughly comparable to a human in their mid-50s through early 70s.
Yes. Breed and body size can influence average lifespan and aging patterns. Size is useful for a general estimate, but dogs of the same size may still age differently.
Yes. Select months instead of years and enter your puppy’s current age. Puppy development changes quickly, so the result should be treated as a general developmental comparison.
SATELLAI helps pet parents better understand their dogs’ location, activity, routines, and everyday wellbeing through connected smart pet technology.
This helps us determine the best collar fit. Our collars fit necks 14-30 inches.
This helps us determine the best product for your situation.
Based on your dog's breed, age, and weight, we'll estimate if the neck size is a match.
Estimating neck size...
Here is the estimated neck size range based on your dog's breed, age, and weight.
Collar range: 14-30 inches
Looks like a great fit
Close to the size limit
May fall outside our collar range
This estimated neck range sits comfortably within our collar size range.
This estimate is close to the limit of our collar size range. To ensure a proper fit, please measure your dog's neck before purchasing.
This estimate may be outside our 14-30 inch collar range. Please measure your dog's neck before moving forward.
This is only an estimate. For the best fit, please measure your dog's neck before purchasing.
This helps us recommend the right product for your space. If you are not sure about the fence size, please use Google Maps to measure your fence size (search your address → right-click → "Measure distance"), or contact us — we can help measure it for you. support@satellai.com | 1-888-595-8226
The distance between your home and the fence boundary affects product selection. If you are not sure about the distance between your home and the fence boundary, please use Google Maps to measure (search your address → right-click → "Measure distance"), or contact us — we can help measure it for you. support@satellai.com | 1-888-595-8226
Our GPS trackers use cellular networks. Signal strength affects virtual fence performance.
GPS signals in your environment may be less stable, which could affect virtual fence accuracy.
The surrounding environment affects GPS accuracy and virtual fence performance.
Our compact GPS tracker designed for smaller dogs with real-time location tracking.
Your pet's neck size may exceed the maximum size of the SATELLAI Collar Go, but the SATELLAI Collar Go can fit any band up to 25 mm wide.
The Collar with an added Beacon for enhanced boundary monitoring in smaller yards.
Our full-featured GPS tracker with virtual fence capabilities for medium to large yards.
Based on your answers, our current products may not be the best match. We'd love to help you find the right solution — please contact our support team for personalized assistance.
Need help? Contact our support team:
Our compact GPS tracker is designed specifically for smaller dogs. Lightweight and comfortable for necks under 14 inches.
Our Collar products are designed for dogs with a neck circumference between 14-30 inches.
If your dog is still growing, check back when they reach full size. Many medium-sized breeds reach a 14+ inch neck by adulthood.
Need help? Contact our support team:
