Age calculator in years, months and days
Calculate age on any date, with total elapsed days and explicit CE or Thai BE input. Free, with no account.
How it works
Count complete months from the birth date, then split into years, months and remaining days. If the target month lacks that day, clamp to its last day. A 29 February anniversary becomes 28 February in a non-leap year.
Example
29 February 2000 to 28 February 2027 is 27 years, 0 months, 0 days using this end-of-month convention.
Does this determine legal age?
This is calendar arithmetic, not a legal eligibility determination. A specific rule may use a different birthday convention. The reference date initially uses today in Thailand and can be changed.