GENERAL TOOL WORKSPACE
Age Calculator
Calculate exact age between two dates in years, months and days.
About this tool
Age Calculator
Calculate exact age between two dates in years, months and days and show total days.
Learn how to calculate exact age between two dates, including completed years, months and days and additional time intervals.
How age is normally counted
The common age system increases age on the birthday. The calculator therefore reports completed years first and then the remaining months and days.
Enter the two dates
Use the date of birth and the date at which you want to know the age. The second date can be today or a future/past reference date.
Why months and days are not simple divisions
Calendar months have different lengths, so exact age needs calendar arithmetic rather than dividing total days by 30.
Additional intervals
The calculator also shows total days so you can use the result for planning, records and date comparisons.
International considerations
Different cultures use different age-counting conventions. Tervilo uses the common birthday-based system and explains that distinction.
Examples
For a person born on January 1, 2000, the age on January 1, 2026 is exactly 26 years. A date between birthdays includes the remaining months and days.
Questions & Answers
Frequently Asked Questions
Can I calculate age on a date other than today?
Yes. Select any valid reference date in the Age at the Date of field.
What does the Age Calculator calculate?
It provides an estimate from the inputs you enter. Review the detailed guide on this page for formulas, interpretation, assumptions and limitations.
Does the calculator show years, months and days?
Yes. The primary result shows completed years, remaining months and days, followed by equivalent elapsed-time units.
What happens if the date of birth is after the reference date?
The calculator rejects the dates and asks you to enter a valid chronological range.