Age & DatesDATE & AGE TOOL
Age in Weeks Calculator
Find your age in completed weeks and see the underlying day count.
How this calculator works
This tool uses calendar dates directly. Date differences are calculated from UTC-normalized calendar dates to avoid daylight-saving-time changes affecting the result. Calendar age counts complete months from the starting date, then remaining days. When a month is shorter, the date is clamped to its last day. For this tool, a 29 February birthday is observed on 28 February in a non-leap year. These are calculation conventions, not legal eligibility rules.
Why use this tool?
It is designed for quick, transparent calculations without requiring an account. Your date inputs are processed in your browser by the current version of the site.
Frequently asked questions
Does this calculator account for leap years?
Yes. Calendar calculations use the actual dates in the Gregorian calendar, including leap years.
Do you store my date of birth?
The calculator processes dates locally in your browser. We do not send the entered dates as analytics events. See our privacy information for site analytics details.
Keep exploring
How do I calculate my age in weeks?
Count the elapsed calendar days from your birth date to the selected date, then divide by seven. Complete weeks are rounded down; the remainder is displayed as extra days. This is chronological age, not pregnancy gestational age.
Worked example
A span of 100 days is 14 complete weeks and 2 days.