Age Calculator
Enter a date of birth and reference date to calculate full age, year age, Korean counting age, elapsed days, and days until the next birthday.
Calculation standard
Focuses on internationally common full age and actual elapsed time.
Global standard focuses on full age based on whether the birthday has passed, which is commonly used for international forms and services.
Usage Tips
Check your age on a specific date, not only today
Enter your date of birth and a reference date to calculate not only your current full age, but also your age on a school start date, contract date, exam date, or travel date. You can also compare year age, Korean counting age, days since birth, and time left until your next birthday.
What is Age Calculator?
The Age Calculator uses a date of birth and reference date to calculate full age, elapsed days, and days until the next birthday. It also provides a Korean standard toggle for year age and Korean counting age, while the global standard focuses on internationally common full-age results.
How to Use
- 1Enter a date of birth.
- 2Set today or another reference date.
- 3Choose Korean standard or global standard.
- 4Use Korean standard when you need full age plus year age and Korean counting age as reference values.
- 5Use global standard when you need internationally common full age and elapsed-time results.
- 6Copy the result when you need to paste it into notes, forms, or documents.
Choose full age or birth-year age for the purpose
Last reviewed: July 11, 2026Age calculation rules
full age = reference year − birth year, subtract one if the birthday has not occurred; year age = reference year − birth year
Full age checks whether the birthday has passed, while year age compares only years. Counting age is a reference convention, not a default for official forms.
A person born on February 29, 2000 at July 11, 2026
- • Birth date 2000-02-29
- • Reference date 2026-07-11
- • Compare Korean and global display modes
- 1. 2026 − 2000 = 26 years
- 2. The 2026 birthday has passed, so full age is 26
- 3. Year age is also 26; counting age is shown only as a reference
Full age is 26 on the reference date, and the time until the next birthday is also available.
How to read the result
- Use full age for international documents and most legal or administrative checks.
- Schools, military service, and eligibility programs may define their own reference date, so read the official notice.
Conditions that change the result
- Leap-day birthday handling in non-leap years can vary by service or institutional rule.
- Year age and counting age can differ from legal full age and cannot replace official proof.
Common input mistakes
- Check the reference date when evaluating past or future eligibility.
- Subtracting only birth years before the birthday makes full age one year too high.
Reference Knowledge
- ●Full age is based on whether the birthday has passed by the reference date.
- ●Year age is the reference year minus the birth year, and Korean counting age starts at one in the birth year.
- ●Korean counting age is a traditional reference value and is not the same as full age.
- ●Global standard is useful for international services, profiles, travel documents, and forms that expect full age.
- ●All calculations run locally in the browser and are not sent to a server.
FAQ
Q.What is the difference between Korean standard and global standard?
Korean standard shows full age together with year age and Korean counting age as reference values. Global standard focuses on full age and actual elapsed time, which is the format most commonly expected by international services and documents.
Q.How are full age, year age, and Korean counting age calculated?
Full age checks whether the birthday has passed by the reference date. Year age subtracts the birth year from the reference year. Korean counting age starts at one in the birth year and increases when the calendar year changes.
Q.Which value should I use for official forms?
Most international forms use full age. For Korean legal and administrative contexts, full age is also the standard, though some institutions may define their own eligibility rules.
Q.Does the next birthday weekday calculation account for leap years?
Yes. The calculator uses the real calendar. For February 29 birthdays in non-leap years, it uses February 28 as the next birthday reference.
Q.Can I calculate age on a past or future date?
Yes. Change the reference date to calculate age on a specific past or future date, which is useful for eligibility checks, travel planning, exams, and service signup requirements.
Q.Is my date of birth stored?
No. The calculation runs locally in your browser. The date of birth and reference date are not sent to a server or stored in a database.
