Age Calculator Guide: How to Calculate Exact Age
Age calculation is a common daily need, from filling forms and applying for documents to calculating retirement dates.
Nominal Age vs Actual Age
Actual Age (Sui): Calculated by calendar birthday, increased only after the birthday passes. This is the standard for official documents.
Nominal Age (Xu Sui): Calculated by lunar year, counted as 1 at birth and increases at each Spring Festival. Still widely used in Chinese tradition.
Precise Age Calculation
To the day: Count complete years, months, and days between two dates. Useful for contract terms and service years.
To the month: Count remaining months when not a full year. Common in alimony calculations.
To the year: Count whole years only. Used for school enrollment age and retirement checks.