Dog Age Calculator
Estimate your dog’s age in human years using the AKC size chart. Enter dog years, months or weeks and choose the dog’s adult size. You can also reverse a human-equivalent chart value. Whole-year chart rows cover ages 1–16; fractional ages use stated interpolation.
- Dog's age
- Adult size
- That band
- over 20–50 lb (about 9–23 kg)
Choose the dog's adult size, including for a puppy or mixed breed. Weight bands select a chart column; they do not predict growth or account for individual breeds.
The AKC table gives whole-year estimates from 1 to 16 dog years. We interpolate between rows and from an illustrative zero anchor to year one. Fractions, including puppy values, are arithmetic approximations. Months are divided by 12; weeks use 7 days and a 365.25-day year. Neither conversion uses a birth date. Switching direction or unit clears the entry so its meaning stays explicit.
The separate 2020 Labrador research formula is not adjusted by the size buttons and does not measure your dog's DNA. Neither model determines health, life stage, care needs or remaining lifespan. The reverse mode inverts the chart only; it cannot find the date you and your dog become the same age.
Dog years to human years chart
AKC whole-year values. Select a dog age to calculate it using the chosen size.
| Dog age | Small | Medium | Large | Giant |
|---|---|---|---|---|
| 15 | 15 | 15 | 12 | |
| 24 | 24 | 24 | 22 | |
| 28 | 28 | 28 | 31 | |
| 32 | 32 | 32 | 38 | |
| 36 | 36 | 36 | 45 | |
| 40 | 42 | 45 | 49 | |
| 44 | 47 | 50 | 56 | |
| 48 | 51 | 55 | 64 | |
| 52 | 56 | 61 | 71 | |
| 56 | 60 | 66 | 79 | |
| 60 | 65 | 72 | 86 | |
| 64 | 69 | 77 | 93 | |
| 68 | 74 | 82 | 100 | |
| 72 | 78 | 88 | 107 | |
| 76 | 83 | 93 | 114 | |
| 80 | 87 | 99 | 121 |
Sources: AKC chart and explanation; UC San Diego's 2020 research summary.
Common questions
- Is one dog year really seven human years?
- The seven-times rule is a rough historical comparison. The AKC chart is nonlinear: at one year, its small, medium and large columns give 15 human years, while giant gives 12. At ten years the columns give 56, 60, 66 and 79. These are estimates, not measurements of an individual dog.
- What formula does this dog age calculator use?
- The main result looks up the AKC’s published whole-year table, rather than adding a fixed rate every year. Between adjacent rows it uses linear interpolation. Below one year it interpolates from an illustrative zero anchor. It does not extrapolate beyond the table’s sixteen-year endpoint.
- Can I enter puppy age in months or weeks?
- Yes. Choose Months or Weeks and enter an ordinary decimal. Six months becomes 0.5 years. Months use 12 per year; weeks use seven days divided by a 365.25-day year, so week conversion is approximate. The puppy human-equivalent result is interpolated, not a developmental assessment.
- Does it calculate age by breed or weight?
- It uses four adult-size bands: up to 20 lb, over 20 to 50 lb, over 50 to 100 lb, and over 100 lb. Kilogram labels are approximate. Choose expected adult size for a puppy and the appropriate adult size for a mixed breed. There is no breed selector or breed-specific lifespan model; a Yorkie, Chihuahua, Labrador, Boxer or Pitbull is not individually modeled.
- What is the Labrador epigenetic formula?
- The separate research illustration uses 16 × ln(dog years) + 31, where ln is the natural logarithm. UC San Diego’s 2020 study compared Labrador and human methylation patterns. One breed cannot establish universal conversion for all dogs. This tool does not analyze DNA and displays the formula only for ages 1–16; that display limit is not a study validation claim.
- Can I convert human years back to dog years?
- Choose Human to dog years and enter a human-equivalent value from the chart. The result inverts the selected column with linear interpolation. Its maximum human input is 80 for small, 87 for medium, 99 for large or 121 for giant, corresponding to sixteen dog years. This is a model comparison, not a person’s biological age.
- Can I calculate dog age by birthday or find our same-age date?
- For calendar age from a known birth date, including completed weeks, use the Age Calculator. This tool accepts supplied numerical ages. It has no birth-date input or paired birthday intersection: lap day, overlap and same-age dates require a separate calculation with a stated aging model.
- Can it discover a rescue dog’s age or determine when it is senior?
- No. You must supply the dog’s age. A conversion chart cannot identify chronological age from appearance, establish life stage, schedule care or predict remaining lifespan. AVMA notes that there is no universal senior age for dogs. The tool does not provide feeding, growth, exercise or heat-cycle recommendations.
- Are my entries saved?
- Valid deliberate edits are saved in this browser. Opening or restoring the calculator does not rewrite saved data. Invalid drafts leave the previous entry intact, and an unusable saved record is retained until you choose Forget saved entry. Changing direction or unit clears the visible input; it does not save that blank draft.
Human-equivalent estimates from an AKC chart, with stated interpolation. The separate Labrador formula does not measure DNA, health or lifespan.