How age is calculated
Subtracting dates sounds simple, but leap years, unequal month lengths and time zones make it fiddly. This calculator walks the calendar properly: full years first, then remaining months, then days — so someone born on February 29 gets a correct age in non-leap years too. Everything runs in your browser; no birth date is ever sent anywhere.
Common uses
Job applications and government forms often ask for age "as of" a specific date — use the Age at date field for that. Parents use it to check school enrollment cutoffs, HR teams verify minimum-age requirements, and the merely curious enjoy seeing their age tick up in seconds.
Frequently asked questions
How accurate is this age calculator?
Fully — it accounts for leap years and varying month lengths, computing down to the second based on your device clock.
What if I was born on February 29?
In non-leap years the calculator treats March 1 as the anniversary for year counting, the common legal convention in most places.
Can I calculate age at a future or past date?
Yes. Leave “Age at date” empty for today, or pick any date — for example, how old you'll be when a contract starts.
Is my birth date stored?
No. The calculation happens locally in JavaScript. Nothing is uploaded or saved.
Why does my age differ from another calculator?
Some calculators ignore leap days or count months as 30 days. This one walks the real calendar, which is the correct method.