Age Calculator | How to use and interpret results
Find completed years of age on a chosen calendar date, with the next birthday nearby. An optional traditional Korean year-count age is a separate display convention.
- Runs in your browser
- Nothing is uploaded
- No signup; device limits apply
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How to use this tool
Choose a birth date and an as-of date; leaving the latter empty uses the browser's current date. Fix that date when comparing historical records or repeating a calculation.
Results and examples
A person born on 2000-09-06 is 25 on 2026-09-05 and turns 26 the next day. Read the as-of date and next birthday together to understand the boundary.
Worked example
A person born on 2000-09-06 is 25 on 2026-09-05 and turns 26 the next day. Read the as-of date and next birthday together to understand the boundary.
Limitations
- Eligibility rules for insurance, school or pensions are not evaluated.
- For a February 29 birthday, this tool uses February 28 as the next birthday in a non-leap year.
Fields
| Field | Guidance and constraints |
|---|---|
| Date of birth | Check the unit and format displayed beside this field. |
| As-of date (leave blank for today) | Check the unit and format displayed beside this field. |
| Also show Korean age (counting age) | Check the unit and format displayed beside this field. |
Data handling
Processing stays in the current browser tab; the site does not upload tool input for the calculation itself.
Sources
Frequently asked questions
What happens the day before a birthday?
A person born on 2000-09-06 is 25 on 2026-09-05 and turns 26 the next day. Read the as-of date and next birthday together to understand the boundary.
Does the result establish legal eligibility?
Eligibility rules for insurance, school or pensions are not evaluated. For a February 29 birthday, this tool uses February 28 as the next birthday in a non-leap year.
