Weeks to Days Converter

The formula is: days = weeks × 7.

Worked example: 3 weeks is 21 days.

To go the other way, use the Days to Weeks Converter, which divides by 7 instead of multiplying.

There are exactly 7 days in a week: Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, and Sunday. The seven day week is usually traced to the Babylonians, who tied it to the seven celestial bodies visible to the naked eye (the Sun, the Moon, Mercury, Venus, Mars, Jupiter, and Saturn). The cycle does not change with months or leap years.

Because 7 does not divide evenly into a 365 day year, the calendar shifts by one weekday each year (two after a leap day), which is why a birthday falls on a different day of the week every year.

Days and Weeks in Pregnancy

According to the American College of Obstetricians and Gynecologists, a pregnancy lasts an average of 40 weeks (280 days) from the first day of the last menstrual period. Converting weeks to days is a quick way to check a due date or a gestational age given in weeks and days.

Common values in weeks and their equivalents in days:

Weeks to days is one of the most practical everyday conversions: a 2 week notice period is 14 days, a 6 week course is 42 days, and a 13 week quarter is 91 days. It also helps with visa and travel rules, rental agreements, and fitness or rehab programs written in weeks.

To count the days between two dates, use the Date Difference Calculator. To count only business days, use the Working Days Counter.

Every time converter that shares a unit with this page, starting with the reverse conversion, one page per pair of units, then the converters that show many units at once.

• Days to Weeks Converter: 1 week = 7 days
• Days to Months Converter: 1 month is 30.4375 days on average
• Days to Years Converter: 1 year is 365.25 days on average
• Hours to Days Converter: 1 day = 24 hours
• Hours to Weeks Converter: 1 week = 168 hours
• Days to Minutes Converter: 1 day = 1,440 minutes
• Seconds to Days Converter: 1 day = 86,400 seconds
• Months to Weeks Converter: 1 month is about 4.348214 weeks on average
• Weeks to Years Converter: 1 year is about 52.178571 weeks on average
• Day Converter: days to hours, minutes, weeks, fortnights, months and years at once
• Hour Converter: hours to minutes, seconds, days, weeks, months and years at once
• Minute Converter: minutes to hours, seconds, days, weeks and more at once
• Seconds Converter: seconds to milliseconds, nanoseconds, minutes, hours and more at once
• Milliseconds Converter: milliseconds to seconds, minutes, microseconds and more at once
• Time Unit Converter: any amount of time in 13 units, from picoseconds to decades