Weeks to Days
A week is seven days, so multiply weeks by 7 to get days: 4 weeks is 28 days, 12 weeks is 84 days and 52 weeks is 364 days. The converter also handles fractions, so 2.5 weeks gives 17.5 days.
1 week = 7 days
1 wk = 7 d · multiply by 7
52 weeks is not quite a year
Fifty-two weeks make 364 days, one short of a common year and two short of a leap year. That spare day is why your birthday moves one weekday later each year, or two after 29 February. It also means a schedule built on 52 weekly cycles slowly drifts against the calendar.
Business calendars use ISO 8601 week numbers to stay consistent. ISO weeks start on Monday, and week 1 is the week containing the year's first Thursday. Years that begin on a Thursday, and leap years that begin on a Wednesday, end up with 53 ISO weeks; 2026 is one of them, because 1 January 2026 fell on a Thursday.
Weeks to days conversion table
Rounded to six significant digits. Change any value in the converter above for an exact figure.
| Weeks (wk) | Days (d) |
|---|---|
| 1 | 7 |
| 2 | 14 |
| 3 | 21 |
| 4 | 28 |
| 5 | 35 |
| 6 | 42 |
| 7 | 49 |
| 8 | 56 |
| 9 | 63 |
| 10 | 70 |
| 12 | 84 |
| 15 | 105 |
| 20 | 140 |
| 25 | 175 |
| 30 | 210 |
| 40 | 280 |
| 50 | 350 |
| 60 | 420 |
| 70 | 490 |
| 75 | 525 |
| 80 | 560 |
| 90 | 630 |
| 100 | 700 |
| Days (d) | Weeks (wk) |
|---|---|
| 1 | 0.142857 |
| 2 | 0.285714 |
| 3 | 0.428571 |
| 4 | 0.571429 |
| 5 | 0.714286 |
| 6 | 0.857143 |
| 7 | 1 |
| 8 | 1.14286 |
| 9 | 1.28571 |
| 10 | 1.42857 |
| 12 | 1.71429 |
| 15 | 2.14286 |
| 20 | 2.85714 |
| 25 | 3.57143 |
| 30 | 4.28571 |
| 40 | 5.71429 |
| 50 | 7.14286 |
| 60 | 8.57143 |
| 70 | 10 |
| 75 | 10.7143 |
| 80 | 11.4286 |
| 90 | 12.8571 |
| 100 | 14.2857 |
How to convert weeks to days
d = wk × 7
1 wk = 7 d
25 wk × 7 = 175 d
- Start with the value in weeks.
- Multiply it by 7.
- Round the result to the precision the job needs: whole numbers for everyday use, more decimals for engineering or recipes.
Weeks in pregnancy, notice periods and leave
Pregnancy is counted from the first day of the last menstrual period, so a full-term 40 weeks is 280 days, about two weeks longer than the time since conception. When a clinician says 12 weeks and 3 days, that is 87 days.
Employment terms switch between calendar days and working days. A two-week notice period is 14 calendar days, which usually contains 10 working days; four weeks of paid leave in a five-day week is 20 working days. Check which one a contract means before converting. The days between dates calculator counts either kind between two dates.
Fortnights and other groupings
A fortnight is 14 days, the standard pay period in many countries and a common term in British and Australian English. A quarter of a year is 13 weeks, or 91 days. To go one step smaller, multiply the days by 24 with days to hours.
Frequently asked questions
- How many days are in 6 weeks?
- 42 days.
- How many days is 40 weeks of pregnancy?
- 280 days, counted from the first day of the last period. Only a small share of babies arrive on that exact date.
- Does every year have 52 weeks?
- Every year has 52 full weeks plus one or two days. In ISO week numbering, some years have 53 weeks to absorb those extra days.
- How many working days are in 3 weeks?
- Usually 15, assuming a Monday-to-Friday schedule and no public holidays in that span.