The short answer: 52 weeks and a bit
A normal year has 365 days. Divide by seven and you get 52 weeks plus one extra day. Leap years, with 366 days, have 52 weeks and two days. That leftover day is why your birthday moves one weekday later each year, and two after a February 29.
When a year has 53 weeks
Under the ISO 8601 week system, a year has 53 weeks when it starts on a Thursday, or when it's a leap year starting on a Wednesday. That happens about 71 times every 400 years, so roughly every five or six years. 2026 has 53 ISO weeks, because January 1, 2026 was a Thursday. The next one after that is 2032.
Why it matters for your paycheck
If you're paid weekly, you usually get 52 paychecks a year, but now and then you'll get 53. With biweekly pay, it's normally 26 paychecks, and every 11 years or so there are 27. Salaried workers paid biweekly sometimes see a slightly smaller check in a 27-pay year, because the same annual salary gets split into more pieces. Worth knowing before you budget.
Weeks in a month
A month averages about 4.35 weeks (52.18 ÷ 12). That's why 'four weeks' and 'one month' aren't the same thing when you're budgeting rent or subscriptions. If you pay a bill every four weeks, you'll pay it 13 times a year, not 12.
Work weeks and vacation
With two weeks of vacation and about 11 federal holidays (see our federal holidays 2027 list), a typical US full-time worker puts in around 48 working weeks. For 40 hours a week, that's roughly 1,920 hours of actual work, versus the 2,080 used in pay calculations.
Counting weeks to an event
Use our days until any date calculator; it shows weeks and days left. Or check what week number it is today.
Frequently asked questions
How many weeks are in 2026?
52 weeks and one day, and 53 ISO weeks.
How many weeks are in a month?
About 4.35 on average.