Resumes, insurance policies, flight bookings, retirement eligibility โ almost everything needs your age. But is your age "last birthday" or something more precise? This guide clears up the confusion and shows you how to compute your exact age in seconds.
Calendar Age, Lunar Age, and Exact Age
| Concept | How it works | Used for |
|---|---|---|
| Calendar age (ๅจๅฒ) | Counts from birth date, +1 each birthday | Legal documents, ID, resumes |
| Lunar age (่ๅฒ) | Born as 1, +1 each Lunar New Year | Traditional customs (mainly East Asia) |
| Exact age | Precise to the day | Medical, actuarial, precise calc |
Calendar age is the international standard โ the only method recognized for official purposes in most of the world.
How to Calculate Calendar Age Precisely
Calendar age = current date โ birth date, subtract 1 if your birthday hasn't arrived this year. Example: born August 15, 1995; today is August 14, 2026 โ birthday not yet reached, so age = 2026 โ 1995 โ 1 = 30.
Computing age to the day is far more accurate. Instead of counting on your fingers, use the age calculator โ enter your birth date and it outputs your exact age to the day, plus days until your next birthday.
Why "Exact Age" Matters
In medicine, insurance actuarial work, and benefit eligibility, age precise to the day is more scientific. Drug dosing calculations, retirement eligibility, and insurance contribution periods all benefit from an exact age. Run the age calculator once and avoid costly age errors.
Other Uses for Date-of-Birth Calculations
- Project timelines: days between two dates
- Tenure / work anniversary: years and months since joining
- Pet age: convert your pet's age to "human years"
- Anniversaries: how many years since you married or met
Frequently Asked Questions
Does age increase on the birthday itself or the day after?
Legally, most jurisdictions count the birthday itself as the day you turn a year older.
How old is someone born in 1990?
It depends on the exact date. Enter the birth date into the age calculator for a precise answer.
Stop guessing your age โ open the age calculator, enter your birth date, and get your exact age to the day plus all date intervals in one go.