Age Calculator
Enter a birth date (and optional as-of date) to get the exact age in years, months, and days, plus the number of days until the next birthday. Everything runs in your browser.
Calculate an age in completed years, months, and days from a date of birth to a selected reference date. The calculator also shows how many days remain until the next birthday and runs entirely in your browser.
How to calculate age
- Enter the date of birth.
- Choose the reference date, or use Today.
- Review the completed years, months, and days.
- Check the next-birthday message for the remaining day count.
How the age calculation works
The calculator subtracts calendar years, months, and days rather than dividing elapsed milliseconds by an average year length. When the day difference is negative it borrows days from the preceding month, and when the month difference is negative it borrows one year.
The next birthday is built from the birth month and day in the reference year. If that date has already passed, the calculator advances it by one year and estimates the remaining days from the date difference.
Privacy and limitations
Dates are processed locally in the browser and are not uploaded to Votilo. The result is a calendar calculation, not a legal or medical age determination. Edge cases such as leap-day birthdays can depend on JavaScript date normalization and local calendar behavior.
Frequently asked questions
Can I calculate age on a past date?
Yes. Set the reference date to the past date you want to evaluate.
Can the birth date be after the reference date?
No. The tool shows an error when the birth date is later than the reference date.
Does it show total days lived?
No. The main result is completed years, months, and days plus the next-birthday countdown.
How is the next birthday calculated?
The birth month and day are placed in the reference year, then moved to the next year if that birthday has already passed.
Are my dates uploaded?
No. The calculation runs locally in your browser.