Printable Calendar 2027 with Week Numbers

How to read it

The narrow column on the left of each month shows the week number for that row. Weeks start on Monday, so each row is one numbered week from Monday to Sunday. A week that starts in one month and ends in the next appears on both pages with the same number. The page shows January to December and moves to the next year in September, when planning for it starts.

The ISO 8601 rules

ISO 8601 is the international standard for writing dates, and its week numbers are the ones the ISOWEEKNUM function returns in Excel and Google Sheets:

• Weeks start on Monday.
• Week 1 is the week with the year’s first Thursday in it, so it always contains 4 January.
• A year has 52 weeks, or 53 when it starts on a Thursday (or on a Wednesday in a leap year).

Because of the Thursday rule, the first days of January can belong to week 52 or 53 of the old year, and the last days of December to week 1 of the new one. That’s why the row with Friday 1 January 2027 is numbered 53: its Thursday is 31 December 2026, and 2026 is a 53-week year. The table below shows where week 1 starts for the years around this one.

ISO or US week numbers?

Set Week starts on to Sunday and the numbers switch to the US convention: weeks run Sunday to Saturday and week 1 is the week that contains 1 January, whatever day that is. That matches WEEKNUM in Excel and Google Sheets with its default setting (Microsoft calls it System 1) on every row but one: the row that spans New Year is numbered 1 because it contains 1 January, while WEEKNUM gives its December days 53, or 54 in a leap year that starts on a Saturday. WEEKNUM with return type 21 gives ISO weeks instead. If a schedule says “week 14”, check which system it uses before you plan around it; around New Year the two can be a week apart.

Layouts that show week numbers

Week numbers print on every layout except the year at a glance. With a month per page they take a slim column of a few percent of the width, so the day boxes stay big enough to write in; the year-at-a-glance sheet has no room for them. Week numbers and fillable day boxes work together, so tick Fillable PDF as well if you’d like to type into the planner.

For UK bank holidays on Monday-first weeks, open the UK calendar; for a planner you can type on, the fillable calendar. Everything else starts from the calendar maker.

ISO week numbers, 2025 to 2029