How many weeks are in a year?

52 weeks and 1 or 2 days

A common year has 365 days: 52 weeks of 7 days make 364, so 1 day is left over. A leap year has 366 days and 2 days left over. Across the 400-year cycle of the Gregorian calendar, which has 97 leap years, the average year is 365.2425 days, or 52.1775 weeks. The converter above starts at 1 year; change it to see how many weeks are in 2, 5 or 10 years, or use weeks to years to go the other way.

The leftover day is why a date moves forward one weekday each year: October 7 was a Tuesday in 2025, a Wednesday in 2026 and is a Thursday in 2027. After February 29, it moves two.

Years with 53 weeks

Calendars that number the weeks — payroll, retail and the ISO 8601 standard used in business planning — need somewhere to put the extra day or two. Every five or six years, they get a week 53. In ISO numbering, a year has 53 weeks when it starts on a Thursday, or when it is a leap year that starts on a Wednesday:

The same drift gives some years 53 Fridays, which means a 53rd weekly paycheck or a 27th biweekly one.

Weeks in months, pay periods and school years

Using 52 weeks in a budget or a plan

For yearly totals, multiply a weekly figure by 52 and remember the extra day: $500 a week is $26,000 over 52 weeks, and one more payday adds $500 in a year that has one. Converting the other way, divide a yearly amount by 52 for a weekly figure — $52,000 a year is $1,000 a week — or by 26 for a biweekly paycheck. Monthly figures need the 4.35 average, not 4: rent of $1,300 a month is about $300 a week, because 1,300 × 12 ÷ 52 = 300. To turn an hourly wage into a yearly figure, the hourly to salary calculator uses 52 weeks. Training plans and school terms usually count whole weeks and ignore the leftover day.

For a period counted from today, such as 90 days from today, the date pages count the weeks and days exactly; for hours worked across weeks, see the hours calculator.