Behind the result - No mystery in the method
Calendar age = entered years + entered months ÷ 12; if only one is entered, the other contributes 0 and this is stated. At integer ages the converter looks up AAHA’s published approximate comparison chart. Dog bands use the chart’s adult-weight categories; cat values use the separate cat column. Between listed whole-year points it linearly interpolates: lower chart value + fractional year × (next value − lower value). This interpolation is an editorial convenience, not a biological model. No human-age number is produced under 1 year or outside the chart range (dogs: 1–20 years, giant dogs: 1–16; cats: 1–21). A missing dog size band is not guessed. Numbers are rounded to one decimal. There is no age × 7 rule, lifespan forecast, diagnosis, screening schedule or assessment of an individual pet. Method reference: AAHA approximate age chart (PDF).
Blank optional text is omitted. Missing numeric inputs and any arithmetic defaults are identified. Text is displayed literally, not interpreted as HTML. The tools do not fetch live vet prices, diagnose health issues, check medical records or replace a veterinarian. The plugin does not store your pet’s details or form inputs.
Results are estimates and general guidance only—not veterinary advice. Have health concerns checked with a vet. For urgent concerns, contact a vet or emergency veterinary clinic rather than using a planner.
Before you go
Is this my pet’s biological age?
No. It is a rough comparison from an age chart, not a test of organs, fitness, cognition or lifespan. Animals of the same age can have very different needs.
Why do dog size and chart limits matter?
The source chart has separate adult-weight categories. Select the appropriate chart band rather than guessing from a breed name. Outside the published range the tool deliberately gives no human-age number.
What if I only know an approximate age?
Enter an estimate only if you are comfortable labeling it as one. The arithmetic cannot make an uncertain birthday precise. A veterinarian can help assess an unknown history.
Can I print the result, and are my pet’s details stored?
Print / Save PDF and Download text create copies you control. The plugin does not save inputs or results to a server, cookies or browser storage. Your browser may restore forms independently. Clear all resets the open page, but cannot erase downloaded files, printouts or browser autofill. Keep personal identifiers out of notes.