🎂 Age Calculator
Exact age in years, months, days and zodiac sign
How it works
This calculator works out an exact age — in years, months, and days — between a birthdate and any target date. That sounds trivial until you remember that months are different lengths and February sometimes has 29 days. The calculation handles leap years, month lengths, and the "borrowing" logic automatically, so you get a precise answer instead of a rough one.
People use it for more than birthdays: figuring out a child's exact age for school enrolment, checking age on a past or future date for legal or insurance purposes, or settling a friendly argument about who is older by how much.
The formula
There is no single tidy equation; it is calendar arithmetic. First, years = target year − birth year, then subtract one year if the birthday has not happened yet in the target year. Then count whole months since the last birthday, borrowing days from the previous month when the target day is earlier than the birth day (using that month's actual length, including leap-year Februaries). The result is the exact years, months, and days lived.
Worked example
Someone born June 8, 1992, on October 4, 2026: years = 2026 − 1992 = 34, and the June birthday has passed, so 34 full years. From June 8 to October 8 would be exactly 4 months, but we are 4 days short of that, so we borrow: 3 full months and (30 − 4) = 26 days. Final answer: 34 years, 3 months, 26 days.
Frequently asked questions
Why does another calculator give me a result one day off?
Usually it is a time-zone or rounding difference, or one calculator counts inclusively (including both endpoints) while another counts exclusively. For everyday purposes both are right.
What about people born on February 29?
In non-leap years most jurisdictions treat the birthday as February 28 or March 1 for legal purposes. The calculator handles the date math; the legal convention depends on where you live.
Can I find my age on a past or future date?
Yes — just set the target date. It works for "how old will I be on my wedding day" just as well as "how old was I when..."