Age Calculator
Calculate exact age from a birth date and a reference date.
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Result
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Calculation method
How to use Age Calculator
Compare a birth date with a reference date to calculate completed years and months.
ExampleIf the birthday has not occurred yet this year, subtract one from the year difference.
Displayed values follow the definitions stated above.
Calculation guide
Exact age changes when the birthday is reached
Exact age subtracts the birth year from the reference year and subtracts one more when that year’s birthday has not yet occurred. It compares calendar dates, not birth times.
Formula usedAge = reference year − birth year − 1 if birthday has not occurred
Completed months count only whole months that have elapsed.
Recommended steps
- Enter the full date of birth.
- Change the reference date for age at a past or future event.
- Use any specific statutory reference date required by the destination.
How to interpret the result
- Age increases on the birthday.
- Completed months include only fully elapsed months.
- Insurance age, school year and gestational age use different rules.
FAQ
Frequently asked questions
Does age increase on the birthday?
Yes. A reference date equal to the birthday counts it as reached.
Does this show Korean counting age?
No. It displays date-based exact age only.
Can I use it for insurance age?
Not necessarily. Policies can use separate six-month rounding rules.
Useful together