Age Calculator
Work out an exact age in seconds. Enter a date of birth and QuickUtila calculates the age today — or on any date you choose — in years, months and days, with totals and a countdown to the next birthday.
Calculated in your browser using calendar dates, so time zones and daylight saving time don’t affect the result.
How Age Is Calculated
Age is counted in completed years first, then completed months, then the remaining days. A year is only complete once the birthday has been reached, and a month is complete once the same day of the month comes around again.
When the birth day doesn’t exist in a month — for example the 31st in a 30-day month — the last day of that month is used as the monthly anniversary.
- 1Born March 15, 1990; age on September 24, 2026
- 2Completed years: March 15, 1990 → March 15, 2026 = 36
- 3Completed months: March 15 → September 15 = 6
- 4Remaining days: September 15 → 24 = 9
Therefore: Age: 36 years, 6 months and 9 days.
Leap Year Birthdays
Someone born on February 29 only has a true birthday every four years. In other years the calculator treats February 28 as the anniversary, so a new year of age is completed on February 28. Some countries use March 1 instead for legal purposes.
When Is an Age Calculator Useful?
- Birthdays and celebrations
- Forms that ask for exact age
- Baby and child milestones
- School entry age checks
- Retirement and pension planning
- Pet ages and anniversaries
Frequently Asked Questions
Count the completed years since your date of birth, then the completed months since your last birthday, then the remaining days. The Age Calculator does this automatically for any date.
Yes. Change the “Age on” date to any date after the date of birth.
In non-leap years the calculator uses February 28 as the birthday, so each year of age is completed on February 28.
Age is measured from birth to the chosen date, so the date of birth must be on or before the “Age on” date.