How it works
The calculator uses the ISO week-date rule based on the Thursday of the selected week.
Input stays in the browser. The static page can be deployed independently for its own host or later custom domain.
Find the ISO week number.
Select a date to see the ISO calendar week, ISO year, weekday, and week range.
Preview placement
336 x 280
Preview placement
728 x 90
Week Number Calculator
Preview placements
Visible placeholders stay on the page until real ad units, account approval, and consent management are connected.
- Top rectangle for above-the-fold inventory.
- Leaderboard near the tool interaction.
- Side rail and bottom sticky placements for larger screens.
Frequently asked questions
Is this tool free?
Yes. This static browser tool is designed to be free to use.
Does this tool upload my input?
No. The tool logic runs locally in your browser unless a future version clearly states otherwise.
Can I use it on mobile?
Yes. The layout is responsive and built for mobile, tablet, and desktop screens.