Age Calculator
🔒 Runs in your browser
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Years
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Months
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Days
Total: days lived
How the age is calculated
Age is computed as calendar years, months and days between the date of birth and the reference date (which defaults to today, but can be set to any date). A year is only counted once the birthday for that year has been reached — the remainder is expressed as whole months and days since the most recent birthday, exactly like counting on a calendar rather than dividing the total number of days.
The Feb 29 rule
A person born on February 29 only has a real anniversary once every four years. In every other (non-leap) year, this calculator celebrates the birthday on February 28 — the conventional rule used by most calendars and legal systems — and applies it consistently both to the age total and to the "next birthday" countdown.
Every calculation runs instantly in your browser as you change either date — nothing is sent to a server.
Frequently asked questions
How is a Feb 29 birthday handled in non-leap years?
A person born on Feb 29 is treated as turning a year older on Feb 28 in years that are not leap years — the calculator applies this rule consistently to both the age total and the "next birthday" countdown.
Can I calculate age as of a date other than today?
Yes — set the "as of" date to any date to see how old someone was, or will be, at that point, not just today.
Is my birth date sent to a server?
No — the calculation runs entirely in your browser; nothing is transmitted or stored.