Week Number Calculator
Find the week number of the year for any date instantly. This tool is useful for payroll, reporting, accounting, project schedules, and business planning.
Result
Week number and calendar details for your selected date.
Week number
22
ISO year
2026
Day of year
147
Weekday
Wednesday
Selected date: 27 May 2026
Month: May
Week range: 25 May 2026 to 31 May 2026
Helpful notes
- This calculator uses ISO week numbering where weeks start on Monday.
- Week 1 is the week that contains the first Thursday of the year.
- Useful for payroll, finance, schedules, sprint planning, and reporting.
What does this tool calculate?
It calculates the week number for a selected date and also shows the weekday, month, year day number, and week range.
Common use cases
Use it for payroll cycles, project tracking, operational reporting, audit references, team planning, and deadline coordination.
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