Dog years to human years chart
The first two rows are the same for every size because dogs mature rapidly early in life. From age three, this chart applies a larger yearly increment to larger dogs. All figures are rounded human-age comparisons.
| Dog age | Small under 9 kg | Medium 9 to 23 kg | Large 23 to 41 kg | Giant over 41 kg |
|---|---|---|---|---|
| 1 year | 15 | 15 | 15 | 15 |
| 2 years | 24 | 24 | 24 | 24 |
| 3 years | 28 | 29 | 30 | 31 |
| 4 years | 32 | 34 | 36 | 38 |
| 5 years | 36 | 39 | 42 | 45 |
| 6 years | 40 | 44 | 48 | 52 |
| 7 years | 44 | 49 | 54 | 59 |
| 8 years | 48 | 54 | 60 | 66 |
| 9 years | 52 | 59 | 66 | 73 |
| 10 years | 56 | 64 | 72 | 80 |
| 11 years | 60 | 69 | 78 | 87 |
| 12 years | 64 | 74 | 84 | 94 |
| 13 years | 68 | 79 | 90 | 101 |
| 14 years | 72 | 84 | 96 | 108 |
| 15 years | 76 | 89 | 102 | 115 |
| 16 years | 80 | 94 | 108 | 122 |
If your dog is between birthdays, the dog age calculator includes additional months.
Which dog size column should I use?
- Small: expected adult weight under 9 kg, or about 20 lb.
- Medium: 9 to 23 kg, or about 21 to 50 lb.
- Large: 23 to 41 kg, or about 51 to 90 lb.
- Giant: over 41 kg, or over 90 lb.
Use expected healthy adult size, not a puppy's current weight. If a dog is on a boundary or its breed has an unusual lifespan, treat both neighbouring columns as a range.
How this chart was calculated
LifeDates assigns 15 human years to dog year one and 24 human years by dog year two. Every later calendar year adds four for small dogs, five for medium dogs, six for large dogs and seven for giant dogs. The medium column therefore follows the practical 15, 24, then five-per-year guideline described by the UC Davis School of Veterinary Medicine. The other columns are simple size adjustments for comparison.
The weight bands reflect those used in the AVMA pet-age chart, rounded to whole kilograms. The exact figures here are the LifeDates model and should not be presented as an AVMA or AAHA clinical conversion.
Why a dog's life stage is more useful
The AAHA Canine Life Stage Guidelines state that size, breed, lifestyle, health and age all affect preventive care. Puppy and young-adult stages relate to growth and maturity. Mature-adult and senior boundaries depend on estimated lifespan, with senior defined broadly as the final quarter of that lifespan.
Worked example
A seven-year-old dog expected to weigh 30 kg as an adult uses the large column. The chart gives about 54 human years: 24 for the first two dog years, plus five later dog years at six human years each. A seven-year-old 7 kg dog uses the small column and gives about 44.
Sources and limitations
- AAHA, 2019 Canine Life Stage Guidelines.
- UC Davis School of Veterinary Medicine, Calculating Your Dog's Age.
- American Veterinary Medical Association, Pets Age Faster Than People.
LifeDates has not clinically validated this chart and this page has not been reviewed by a veterinarian. Sources were checked on 27 August 2026. Calendar age is exact only when the birth date is known. Every human-age equivalent is approximate.
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