Find how many weeks a year has. Enter any year to see the weeks, days, ISO week count, weekdays and weekend days, with leap years handled. Free, private, and runs entirely in your browser.
A common year has 365 days and a leap year has 366. Dividing by 7 gives the weeks, and counting from the weekday on which the year begins gives the weekdays. ISO weeks follow the rule that week 1 contains the first Thursday.
How many weeks are in a year? There are 52.14 weeks in a common year of 365 days and 52.29 in a leap year of 366 days. Most calendars show 52 or 53 numbered weeks.
Why do some years have 53 weeks? Because 52 weeks is only 364 days. The extra one or two days add up, so some years have 53 ISO weeks.
2026 has 365 days, which is 365 ÷ 7 = 52.14 weeks, or 52 weeks and 1 day. It begins on a Thursday, so it has 53 ISO weeks and 261 weekdays. 2024 was a leap year with 366 days, 52 ISO weeks and 262 weekdays.
How many weeks are in a month? On average 4.35 weeks, since 52.14 ÷ 12 = 4.345.
How many working weeks are in a year? About 52 minus the weeks of paid leave and holidays. A 40-hour week over 52 weeks is 2,080 hours.
The seven-day week is very old, with roots in ancient Babylon and the Hebrew calendar, and it has run without interruption for centuries. The ISO 8601 standard, first published in 1988, fixed how weeks are numbered so that businesses across countries could agree on week 1 and on years with 52 or 53 weeks.
Use this calculator to plan project schedules, payroll, school terms and subscriptions measured in weeks. A 52-week plan is really 364 days, so it drifts by a day or two each year. Change the year to see how leap years and the starting weekday change the counts.
How many days are in 52 weeks? 364 days, one day short of a common year.
How many hours are in a year? There are 8,760 hours in a common year and 8,784 in a leap year. The hours in a year calculator gives the full breakdown.