Week Number Calculator
Calculated in your browser — we never store your dataVerified formulas with automated testing
📅
Date & Time
Week Number
42
of 53 weeks in 2026
Week 42
Week 42 Dates
Year Progress
Week Number 42 of 5379%
11 weeks remaining in 2026
Jump to Week
ISO Week Numbering
- • • Weeks start on Monday and end on Sunday
- • • Week 1 contains the first Thursday of the year
- • • Week 1 always contains January 4th
- • • Most years have 52 weeks, some have 53
Sources & Methodology
Formula:
ISO 8601 week numberingISO week number calculation
Source: ISO 8601 Date and Time Standard
Stay Updated
Get new calculators and tips delivered to your inbox.