Calendar with week numbers
ISO week numbers printed down the margin of every month, so "week 32" means the same thing to you as it does to everyone else you work with.
Which numbering this uses
These are ISO 8601 week numbers, the standard used across Europe and by most project and payroll software. Week 1 is the week containing the first Thursday of January, which means the first days of a year can belong to week 52 or 53 of the year before.
ISO weeks always run Monday to Sunday, whatever you set the calendar itself to. That is deliberate: if the numbering shifted with the layout, the numbers would stop matching everyone else.
Why a year can have 53 weeks
Most years have 52 ISO weeks. A year gets 53 when it starts on a Thursday, or when it starts on a Wednesday and is a leap year. That extra week catches people out in payroll and in any plan built on "52 weeks", which is a good reason to have the numbers printed where you can see them.
Where the numbers appear
- Month view — a narrow column down the left of the grid, one number per row.
- Year view — the same column inside each of the twelve mini-months.
- Week view — the week number sits beside the heading.
- Day view — printed in the day’s summary line, along with the day of the year.
Week numbers by year
How many ISO weeks each year has, and where week 1 starts. Each year links to the full list of weeks with the dates they cover.
| Year | ISO weeks | Week 1 starts | Last week ends |
|---|---|---|---|
| 2025 | 52 | December 30, 2024 | December 28, 2025 |
| 2026 | 53 | December 29, 2025 | January 3, 2027 |
| 2027 | 52 | January 4, 2027 | January 2, 2028 |
| 2028 | 52 | January 3, 2028 | December 31, 2028 |
| 2029 | 52 | January 1, 2029 | December 30, 2029 |
| 2030 | 52 | December 31, 2029 | December 29, 2030 |
Pick a year
The settings above stay as they are — only the year changes.
- Week numbers 2025
- Week numbers 2026
- Week numbers 2027
- Week numbers 2028
- Week numbers 2029
- Week numbers 2030
Frequently asked questions
What are ISO week numbers?
The week-numbering rule of ISO 8601, used across Europe and by most project and payroll software: weeks run Monday to Sunday, and week 1 is the week that contains the first Thursday of January — so 4 January is always in week 1.
Why do some years have 53 weeks?
A year has 53 ISO weeks when it starts on a Thursday, or on a Wednesday in a leap year; every other year has 52. The table above says which applies to each year.
Do the week numbers change if the week starts on Sunday?
No. The printed numbers stay ISO week numbers, which are Monday-based, whatever the grid does — so week 32 on your calendar is week 32 on everyone else’s.
Is the calendar with week numbers free?
Yes. The PDF is generated in your browser, with no sign-up and no watermark, and it is yours to use — commercially too.