Age in Weeks Calculator
Count how many weeks old someone is, with the leftover days.
What is Age in Weeks?
Weeks are the unit parents, paediatric schedules and pregnancy milestones use — “twelve weeks”, “six weeks old”. A total-week count is the day count divided by seven, but the remainder is worth keeping: 52 weeks and 3 days is more informative than a rounded 52.
How it works
The exact day difference between the birth date and the reference date is computed at local midnight, then divided by seven: the quotient is whole weeks and the remainder is the leftover days. Because it is built on the same exact day count as the age-in-days tool, the two always agree.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Paste or type any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
Nothing is uploaded — every tool in this category runs entirely in your browser.