Week Numbers Calculator
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Week 1
30
31
1
2
3
4
5
Dec 30 - Jan 5, 2025
Week 2
6
7
8
9
10
11
12
Jan 6 - Jan 12, 2025
Week 3
13
14
15
16
17
18
19
Jan 13 - Jan 19, 2025
Week 4
20
21
22
23
24
25
26
Jan 20 - Jan 26, 2025
Week 5
27
28
29
30
31
1
2
Jan 27 - Feb 2, 2025
Week 6
3
4
5
6
7
8
9
Feb 3 - Feb 9, 2025
Week 7
10
11
12
13
14
15
16
Feb 10 - Feb 16, 2025
Week 8
17
18
19
20
21
22
23
Feb 17 - Feb 23, 2025
Week 9
24
25
26
27
28
1
2
Feb 24 - Mar 2, 2025
Week 10
3
4
5
6
7
8
9
Mar 3 - Mar 9, 2025
Week 11
10
11
12
13
14
15
16
Mar 10 - Mar 16, 2025
Week 12
17
18
19
20
21
22
23
Mar 17 - Mar 23, 2025
Week 13
24
25
26
27
28
29
30
Mar 24 - Mar 30, 2025
Week 14
31
1
2
3
4
5
6
Mar 31 - Apr 6, 2025
Week 15
7
8
9
10
11
12
13
Apr 7 - Apr 13, 2025
Week 16
14
15
16
17
18
19
20
Apr 14 - Apr 20, 2025
Week 17
21
22
23
24
25
26
27
Apr 21 - Apr 27, 2025
Week 18
28
29
30
1
2
3
4
Apr 28 - May 4, 2025
Week 19
5
6
7
8
9
10
11
May 5 - May 11, 2025
Week 20
12
13
14
15
16
17
18
May 12 - May 18, 2025
Week 21
19
20
21
22
23
24
25
May 19 - May 25, 2025
Week 22
26
27
28
29
30
31
1
May 26 - Jun 1, 2025
Week 23
2
3
4
5
6
7
8
Jun 2 - Jun 8, 2025
Week 24
9
10
11
12
13
14
15
Jun 9 - Jun 15, 2025
Week 25
16
17
18
19
20
21
22
Jun 16 - Jun 22, 2025
Week 26
23
24
25
26
27
28
29
Jun 23 - Jun 29, 2025
Week 27
30
1
2
3
4
5
6
Jun 30 - Jul 6, 2025
Week 28
7
8
9
10
11
12
13
Jul 7 - Jul 13, 2025
Week 29
14
15
16
17
18
19
20
Jul 14 - Jul 20, 2025
Week 30
21
22
23
24
25
26
27
Jul 21 - Jul 27, 2025
Week 31
28
29
30
31
1
2
3
Jul 28 - Aug 3, 2025
Week 32
4
5
6
7
8
9
10
Aug 4 - Aug 10, 2025
Week 33
11
12
13
14
15
16
17
Aug 11 - Aug 17, 2025
Week 34
18
19
20
21
22
23
24
Aug 18 - Aug 24, 2025
Week 35
25
26
27
28
29
30
31
Aug 25 - Aug 31, 2025
Week 36
1
2
3
4
5
6
7
Sep 1 - Sep 7, 2025
Week 37
8
9
10
11
12
13
14
Sep 8 - Sep 14, 2025
Week 38
15
16
17
18
19
20
21
Sep 15 - Sep 21, 2025
Week 39
22
23
24
25
26
27
28
Sep 22 - Sep 28, 2025
Week 40
29
30
1
2
3
4
5
Sep 29 - Oct 5, 2025
Week 41
6
7
8
9
10
11
12
Oct 6 - Oct 12, 2025
Week 42
13
14
15
16
17
18
19
Oct 13 - Oct 19, 2025
Week 43
20
21
22
23
24
25
26
Oct 20 - Oct 26, 2025
Week 44
27
28
29
30
31
1
2
Oct 27 - Nov 2, 2025
Week 45
3
4
5
6
7
8
9
Nov 3 - Nov 9, 2025
Week 46
10
11
12
13
14
15
16
Nov 10 - Nov 16, 2025
Week 47
17
18
19
20
21
22
23
Nov 17 - Nov 23, 2025
Week 48
24
25
26
27
28
29
30
Nov 24 - Nov 30, 2025
Week 49
1
2
3
4
5
6
7
Dec 1 - Dec 7, 2025
Week 50
8
9
10
11
12
13
14
Dec 8 - Dec 14, 2025
Week 51
15
16
17
18
19
20
21
Dec 15 - Dec 21, 2025
Week 52
22
23
24
25
26
27
28
Dec 22 - Dec 28, 2025
Week 1
29
30
31
1
2
3
4
Dec 29 - Jan 4, 2026
How to Use
- 1. Select a date to find its week number
- 2. Or enter a week number to find its dates
- 3. Choose the year for week number lookup
- 4. View the results instantly
About ISO Week Numbers
- • Weeks start on Monday
- • Week 1 contains January 4th
- • Weeks can belong to different years
- • Used in business and project planning