InterpretationThis is an estimated range
Time zones, leap days and local rules can affect boundary dates. The tool counts complete calendar years, months and days.
Not a diagnosisFor general health education and estimation only. It does not diagnose a condition and is not treatment, medication, diet or training advice.
01Formula used
target date − birth date (calendar difference)Suitable population
Calendar-age calculation between two valid Gregorian dates.
02When not to use it
Legal age, insurance age and traditional age systems may use different rules.
Data error and uncertainty
Input accuracy, measurement technique, rounding and individual variation all affect the result. Internal precision is retained and only displayed values are rounded.
03When to seek help
Medical and legal forms should follow identity documents and the relevant authority rules.
Reference
ISO 8601 Date and time format ↗