Week Calculator

To count weeks between two dates, first find the total number of days separating them. Then divide that number by 7 — the whole number part gives you full weeks, and any remainder is the leftover days. For example, 25 days equals 3 weeks and 4 days.

When you check 'Include end date', one extra day is added to the total count, meaning the end date itself is counted as part of the range. For example, from Monday to Friday is 4 days without the end date, but 5 days with it included.

A standard year has 365 days, which equals 52 weeks and 1 day. A leap year has 366 days, giving 52 weeks and 2 days. So no regular year contains exactly 52 full weeks.

No. 52 weeks × 7 days = 364 days, which is one day short of a standard 365-day year. A leap year has 366 days, so it has 52 weeks plus 2 extra days. This is why the calendar shifts by one (or two) day(s) each year.

This varies by country and culture. In the United States and Canada, Sunday is traditionally considered the first day of the week. In most of Europe and per the ISO 8601 standard, Monday is the first day of the week.

Yes. Knowing the exact number of weeks between a project start and deadline helps you divide work into weekly sprints, set milestones, and manage timelines more effectively. Simply enter your kick-off date and due date to see the full picture.

The calculator will detect that the end date is earlier than the start date and display an error. Make sure your end date is on or after your start date for a valid result.

The calculator uses precise date arithmetic based on the Gregorian calendar, accounting for leap years and varying month lengths. It is accurate for any date range you enter within the supported date format.