Age Calculator
A free tool that instantly calculates your exact age, counting age, year age, days lived so far, and days until your next birthday from just your date of birth. All calculations happen in your browser, so the values you enter are never sent anywhere.
Family birthday favorites
Names and dates of birth are stored only on this device.Enter your date of birth and press Calculate to see the results.
How to use
- Select your date of birth.
- Change the reference date if needed. Leave it empty to calculate as of today.
- Press "Calculate" to see your exact age, counting age, and year age.
Calculation basis and verification sources
Full age is the base year minus the birth year, minus one if that year's birthday has not arrived. Korea's Civil Act Article 158 and General Act on Public Administration Article 7-2 use age in completed years unless a special rule applies. For a Feb. 29 birth, the Korean default advances on Mar. 1 in a non-leap year; a Feb. 28 comparison option is also available.
Law checked: 2026-08-07. Korean counting age and year age are comparison values, not legal determinations. Where elections, military duty, youth protection, pensions, or another law defines a different age or cutoff time, that specific rule and the responsible authority prevail.
Frequently asked questions
How is the exact age calculated?
Exact age starts at 0 in the year you are born and increases by one each time your birthday passes. If this year's birthday hasn't come yet, it is one or two years less than the counting age.
What are counting age and year age?
Counting age starts at 1 at birth and adds a year each New Year, while year age is the current year minus the birth year.
Is the date of birth I enter sent to a server?
No. All calculations happen inside your browser, and the values you enter are not sent to any external server.
Practical example and verification criteria
Age Calculator: Before calculating, check whether amounts are before or after tax, whether a term is in days, months, or years, whether a rate is annual or monthly, and whether start and end dates are inclusive. Align body measurements and currency, length, and time units as well. On-screen defaults may be illustrative assumptions, so replace them with your own conditions.
Age Calculator: For a quick check, start with 2000-08-07 → 2026-08-07 = 26 as a small input whose result relationship you can verify directly. Confirm that the input summary, units, and options match your intent before applying the tool to real values or a copy of the source; this reduces setup mistakes.
Age Calculator: Read the input summary and formula, then check reversible relationships such as principal plus interest, net amount plus tax, or start date plus term. Test values around rounding, zero, one, and date boundaries. Compare health, finance, tax, and administrative results with current official information for the applicable region and effective date.
Age Calculator · Work record: For real work, record the input conditions, selected options, and result together. Do not assume the same state will remain after a refresh or device change. Preserve important results separately using copy, download, a screenshot, or another method the page supports, then reopen them in the target environment.
Age Calculator · Error check: If an error or unexpected result appears, reduce the input, run again with default options, and then change one condition at a time. Recording error messages and boundary values helps distinguish format issues, unsupported cases, and browser resource limits, and prevents an empty result from being mistaken for success.
Age Calculator · Scope of use: Check the page guidance for browser processing versus server lookup, storage location, and supported scope. Use sensitive source material or secrets only when strictly necessary. High-impact work such as legal, financial, or medical decisions or changes to an operational system requires current authoritative information and a separate verification process.