Age Calculator
Enter a date of birth and get an exact age broken down into years, months, weeks, days, hours, and seconds. Birthdays, official forms, and curiosity checks all benefit from the same precise arithmetic.
How to use the Age Calculator
- Enter the date of birth in the date field.
- Optionally set a target date if you want the age on a specific day.
- The full age breakdown appears instantly.
- Read the result as total years and months plus finer-grained units.
When the Age Calculator is useful
- Filling age fields on forms that require exact years and months.
- Checking whether someone turns a milestone age before an event date.
- Verifying school enrollment or sports league age cutoffs.
- Answering the classic question of precisely how old you are today.
How the Age Calculator works
Age is not a subtraction of years alone: the calculator counts calendar boundaries, so someone born in late March is a full year older only after their birthday passes, with the remainder expressed in months and days. Totals in weeks, days, hours, and seconds come from continuous elapsed time since the birth moment. The math runs locally on your device, so nothing you enter leaves the browser.
Limits to keep in mind
Accuracy assumes the entered birth date is correct; the tool calculates calendar age and does not account for time zones unless a target date matters.
Frequently asked questions
Why does the month count matter for age?
Official forms often require age as completed years plus months, especially for children, and rounding would be wrong.
Can I calculate age at a past or future date?
Yes, set the target date and the age reflects that specific day.
Does it handle leap-year birthdays?
Yes, February 29 birthdays roll to March 1 in non-leap years, following common convention.
Last reviewed: October 2026.