| Week 1 | December 30, 2024 – January 5, 2025 |
| Week 2 | January 6 – January 12, 2025 |
| Week 3 | January 13 – January 19, 2025 |
| Week 4 | January 20 – January 26, 2025 |
| Week 5 | January 27 – February 2, 2025 |
| Week 6 | February 3 – February 9, 2025 |
| Week 7 | February 10 – February 16, 2025 |
| Week 8 | February 17 – February 23, 2025 |
| Week 9 | February 24 – March 2, 2025 |
| Week 10 | March 3 – March 9, 2025 |
| Week 11 | March 10 – March 16, 2025 |
| Week 12 | March 17 – March 23, 2025 |
| Week 13 | March 24 – March 30, 2025 |
| Week 14 | March 31 – April 6, 2025 |
| Week 15 | April 7 – April 13, 2025 |
| Week 16 | April 14 – April 20, 2025 |
| Week 17 | April 21 – April 27, 2025 |
| Week 18 | April 28 – May 4, 2025 |
| Week 19 | May 5 – May 11, 2025 |
| Week 20 | May 12 – May 18, 2025 |
| Week 21 | May 19 – May 25, 2025 |
| Week 22 | May 26 – June 1, 2025 |
| Week 23 | June 2 – June 8, 2025 |
| Week 24 | June 9 – June 15, 2025 |
| Week 25 | June 16 – June 22, 2025 |
| Week 26 | June 23 – June 29, 2025 |
| Week 27 | June 30 – July 6, 2025 |
| Week 28 | July 7 – July 13, 2025 |
| Week 29 | July 14 – July 20, 2025 |
| Week 30 | July 21 – July 27, 2025 |
| Week 31 | July 28 – August 3, 2025 |
| Week 32 | August 4 – August 10, 2025 |
| Week 33 | August 11 – August 17, 2025 |
| Week 34 | August 18 – August 24, 2025 |
| Week 35 | August 25 – August 31, 2025 |
| Week 36 | September 1 – September 7, 2025 |
| Week 37 | September 8 – September 14, 2025 |
| Week 38 | September 15 – September 21, 2025 |
| Week 39 | September 22 – September 28, 2025 |
| Week 40 | September 29 – October 5, 2025 |
| Week 41 | October 6 – October 12, 2025 |
| Week 42 | October 13 – October 19, 2025 |
| Week 43 | October 20 – October 26, 2025 |
| Week 44 | October 27 – November 2, 2025 |
| Week 45 | November 3 – November 9, 2025 |
| Week 46 | November 10 – November 16, 2025 |
| Week 47 | November 17 – November 23, 2025 |
| Week 48 | November 24 – November 30, 2025 |
| Week 49 | December 1 – December 7, 2025 |
| Week 50 | December 8 – December 14, 2025 |
| Week 51 | December 15 – December 21, 2025 |
| Week 52 | December 22 – December 28, 2025 |
2025 has 52 ISO weeks. Most years have 52; a year has 53 when it starts on a Thursday (or on a Wednesday in a leap year).
Week 1 of 2025 starts on Monday, December 30, 2024 — ISO week 1 is the week containing the year's first Thursday, so it can start in late December.
=ISOWEEKNUM(A1) returns the ISO week number of the date in A1 (the numbering used on this page); =WEEKNUM(A1) uses the US Sunday-start convention. Both work in Excel and Google Sheets.