How to use it
- Enter the date of birth.
- Leave the second field blank to use today, or set a date to find the age on that day.
- Read the exact age, the totals in months, weeks, days and hours, and the countdown to the next birthday.
How age is calculated
The calculator uses the standard Western method: your age increases on your birthday. It counts complete years first, then complete months, then the remaining days. Because months have different lengths, the "days" part is measured against the actual calendar rather than a fixed 30-day month.
Years = complete years since birth
Months = complete months since the last birthday
Days = days since the last monthly anniversary
Worked example
Someone born on May 14, 1996, measured on September 15, 2026, is 30 years, 4 months and 1 day old. That is 364 months, 1,583 weeks and 11,081 days. They were born on a Tuesday, and their next birthday is 241 days away.
Leap year birthdays
People born on February 29 have a birthday only once every four years. For age purposes, most US jurisdictions treat the birthday as falling on March 1 in common years, while some places use February 28. This calculator uses the last valid day of the month, so a February 29 birth date is counted on February 28 in common years. The difference is one day and only matters in unusual legal situations.
Age reckoning around the world
Not every culture counts age the same way. Korea historically used a system in which a baby is one at birth and everyone gains a year on New Year's Day, which could make someone "two years old" a day after being born. South Korea standardized on the international system in 2023 for most official purposes. East Asian age reckoning still appears in cultural contexts, so if you are comparing ages across systems, say which one you mean.
Where an exact age matters
- School enrollment: cutoff dates are usually set to a specific day, so a few days can change the year a child starts.
- Youth sports: age groups are often set by age on a fixed date, not by grade.
- Retirement accounts and benefits: eligibility rules can hinge on the month you turn a certain age.
- Medical dosing and pediatric charts, where age in months matters for infants.
- Forms and visas, where age is measured on the application date rather than today.
Age in weeks and days for babies
Parents and pediatricians often use weeks for the first months. The calculator gives total weeks and total days, which is easier than counting on a calendar. For premature babies, doctors sometimes use corrected age, measured from the original due date instead of the birth date. To get that, enter the due date rather than the birth date.
Common age milestones in the US
Several everyday rules depend on an exact age rather than a birth year. In most states you can get a learner's permit between 15 and 16, a full driver's license at 16 to 18, and you can vote in federal elections at 18. Car rental companies usually add a young-driver surcharge below 25, and many retailers offer senior discounts starting somewhere between 55 and 65. Social Security has its own set of ages, including early retirement at 62 and a full retirement age that depends on your birth year. Because the exact rules vary by state and by company, use this calculator to confirm the precise age and then check the official requirement.
Privacy
The date you enter never leaves your device. Nothing is uploaded, stored or logged, which matters when the input is a real birth date. You can share a calculation only if you choose to copy the link yourself.
Frequently asked questions
How do I calculate my exact age?
Enter your date of birth above. The calculator counts complete years, then months, then remaining days up to today.
How many days old am I?
The calculator shows total days, weeks, months and hours along with your age in years.
How does the calculator handle February 29 birthdays?
In common years it counts the birthday on February 28, the last valid day of that month.
Can I find my age on a future date?
Yes. Enter a date in the second field to see your age on that day.
What day of the week was I born?
The result includes the weekday of your birth date.
Last reviewed on by the Dailycaltor team.