What week number is it today in 2026?

Today is ISO week 14 of 2026. The ISO 8601 week number system starts on Monday, and Week 1 is the week containing the first Thursday of the year.

What is the ISO 8601 week number standard?

ISO 8601 is the international standard for week numbering. Weeks run Monday to Sunday, and Week 1 is defined as the week containing the year's first Thursday. This means a year has either 52 or 53 full weeks.

How many weeks are in a year?

Most years have 52 ISO weeks. Some years have 53 weeks — this happens when January 1 falls on a Thursday, or on a Wednesday in a leap year.

Free Online Tool

Week Number Calculator

Find the ISO week number for any date. See which week of the year a date falls in — essential for business reporting and project planning.

Today is Tuesday, March 31, 2026

→ ISO Week 14 of 2026

Select a Date

ISO Week Number

Week 14 of 53 — 2026

Week Starts (Monday)

March 30, 2026

Week Ends (Sunday)

April 5, 2026

Day 90

Day of Year

Tuesday

Weekday

Quarter

Weeks in Year

What is a Week Number?

Week numbers are used in business, finance, and project management to reference specific weeks of the year. This calculator uses the ISO 8601 standard, where weeks start on Monday, and Week 1 is the week containing the first Thursday of the year.

📊 Business Reporting

Financial quarters and weekly reports often reference ISO week numbers for global consistency.

🏗️ Project Management

Agile sprints and project schedules often use week numbers for clear communication across time zones.

📅 ISO 8601 Standard

The international standard ensures week 1 always contains January 4th, with Monday as the first day.