Weeks in a Year Calendar
Look up the number of ISO weeks in any year and open the full week-by-week calendar.
Continue with another calculation
Core Week Calculator
Convert dates to ISO weeks, turn week numbers into date ranges, calculate weeks between dates, add/subtract weeks and count from today.
Open →Planning Calculators
Plan deadlines, project timelines, payroll periods, work anniversaries and timesheet weeks.
Open →Week Calendar
Browse ISO weeks by year with Monday-to-Sunday ranges and highlighted current week.
Open →When to use this tool
Most ISO years have 52 weeks, but some have 53. This tool shows which type of year you selected.
Practical uses
Look up the number of ISO weeks in any year and open the full week-by-week calendar.
These planning tools are designed for quick answers, but they also work well as part of a bigger workflow. You can pair them with the year calendar, current week page and week guides to plan projects, delivery windows, payroll cycles, reporting periods and deadlines.
FAQ
Why do some years have 53 weeks?
The weekday alignment can create an extra complete ISO week.
Can I open the full calendar from here?
Yes. The result links to the yearly week calendar page for the selected year.