How do you convert weeks to days?
Multiply the number of weeks by 7. If your figure concerns working days, multiply by 5 instead: six weeks is 42 calendar days but 30 working days.
wk = d ÷ 7
Common durations in weeks and days
| 1 wk | 7 d |
| 2 wk | 14 d |
| 3 wk | 21 d |
| 4 wk | 28 d |
| 6 wk | 42 d |
| 8 wk | 56 d |
| 12 wk (a quarter) | 84 d |
| 26 wk | 182 d |
| 40 wk (pregnancy) | 280 d |
| 52 wk | 364 d |
| 104 wk | 728 d |
Show every value
- 1 wk = 7 d
- 2 wk = 14 d
- 3 wk = 21 d
- 4 wk = 28 d
- 5 wk = 35 d
- 6 wk = 42 d
- 7 wk = 49 d
- 8 wk = 56 d
- 9 wk = 63 d
- 10 wk = 70 d
- 11 wk = 77 d
- 12 wk = 84 d
- 13 wk = 91 d
- 14 wk = 98 d
- 15 wk = 105 d
- 16 wk = 112 d
- 17 wk = 119 d
- 18 wk = 126 d
- 19 wk = 133 d
- 20 wk = 140 d
- 21 wk = 147 d
- 22 wk = 154 d
- 23 wk = 161 d
- 24 wk = 168 d
- 25 wk = 175 d
- 26 wk = 182 d
- 27 wk = 189 d
- 28 wk = 196 d
- 29 wk = 203 d
- 30 wk = 210 d
- 31 wk = 217 d
- 32 wk = 224 d
- 33 wk = 231 d
- 34 wk = 238 d
- 35 wk = 245 d
- 36 wk = 252 d
- 37 wk = 259 d
- 38 wk = 266 d
- 39 wk = 273 d
- 40 wk = 280 d
- 41 wk = 287 d
- 42 wk = 294 d
- 43 wk = 301 d
- 44 wk = 308 d
- 45 wk = 315 d
- 46 wk = 322 d
- 47 wk = 329 d
- 48 wk = 336 d
- 49 wk = 343 d
- 50 wk = 350 d
- 51 wk = 357 d
- 52 wk = 364 d
- 53 wk = 371 d
- 54 wk = 378 d
- 55 wk = 385 d
- 56 wk = 392 d
- 57 wk = 399 d
- 58 wk = 406 d
- 59 wk = 413 d
- 60 wk = 420 d
- 61 wk = 427 d
- 62 wk = 434 d
- 63 wk = 441 d
- 64 wk = 448 d
- 65 wk = 455 d
- 66 wk = 462 d
- 67 wk = 469 d
- 68 wk = 476 d
- 69 wk = 483 d
- 70 wk = 490 d
- 71 wk = 497 d
- 72 wk = 504 d
- 73 wk = 511 d
- 74 wk = 518 d
- 75 wk = 525 d
- 76 wk = 532 d
- 77 wk = 539 d
- 78 wk = 546 d
- 79 wk = 553 d
- 80 wk = 560 d
- 81 wk = 567 d
- 82 wk = 574 d
- 83 wk = 581 d
- 84 wk = 588 d
- 85 wk = 595 d
- 86 wk = 602 d
- 87 wk = 609 d
- 88 wk = 616 d
- 89 wk = 623 d
- 90 wk = 630 d
- 91 wk = 637 d
- 92 wk = 644 d
- 93 wk = 651 d
- 94 wk = 658 d
- 95 wk = 665 d
- 96 wk = 672 d
- 97 wk = 679 d
- 98 wk = 686 d
- 99 wk = 693 d
- 100 wk = 700 d
- 125 wk = 875 d
- 150 wk = 1,050 d
- 175 wk = 1,225 d
- 200 wk = 1,400 d
- 225 wk = 1,575 d
- 250 wk = 1,750 d
- 275 wk = 1,925 d
- 300 wk = 2,100 d
- 325 wk = 2,275 d
- 350 wk = 2,450 d
- 375 wk = 2,625 d
- 400 wk = 2,800 d
- 425 wk = 2,975 d
- 450 wk = 3,150 d
- 475 wk = 3,325 d
- 500 wk = 3,500 d
- 550 wk = 3,850 d
- 600 wk = 4,200 d
- 650 wk = 4,550 d
- 700 wk = 4,900 d
- 750 wk = 5,250 d
- 800 wk = 5,600 d
- 850 wk = 5,950 d
- 900 wk = 6,300 d
- 950 wk = 6,650 d
- 1,000 wk = 7,000 d
- 1,500 wk = 10,500 d
- 2,000 wk = 14,000 d
- 2,500 wk = 17,500 d
- 3,000 wk = 21,000 d
- 3,500 wk = 24,500 d
- 4,000 wk = 28,000 d
- 4,500 wk = 31,500 d
- 5,000 wk = 35,000 d
- 5,500 wk = 38,500 d
- 6,000 wk = 42,000 d
- 6,500 wk = 45,500 d
- 7,000 wk = 49,000 d
- 7,500 wk = 52,500 d
- 8,000 wk = 56,000 d
- 8,500 wk = 59,500 d
- 9,000 wk = 63,000 d
- 9,500 wk = 66,500 d
- 10,000 wk = 70,000 d
The seven-day week has no astronomical basis: it is a convention inherited from the Babylonian and Hebrew calendars, unrelated to the lunar month or the year. ISO 8601 starts it on Monday and numbers weeks 01 to 52 or 53 depending on the year. Methodology & sources.
Frequently asked questions
Why isn't 52 weeks a year?
Because 52 × 7 = 364, so one day is left over, two in leap years. That remainder is what shifts a given weekday's date by one each year, and what produces ISO years with 53 weeks.
How many months is a 40-week pregnancy?
280 days, roughly nine months and a week. The mismatch comes from an average month being 30.44 days rather than 28: four weeks is not a month, and over nine months the gap adds up to a good ten days.
Does a two-week notice run in working days?
Unless stated otherwise it runs in calendar days: 14 days, weekends included. When a contract means working days it says so explicitly, and two weeks then become 10 working days spread over at least 14 real ones.
Does the week start on Monday or Sunday?
It depends on the region. ISO 8601, followed across Europe, starts it on Monday; the United States, Canada and Japan start it on Sunday. That does not change its length, but it does change the week number of a given date.
Why do some companies count in four-week periods?
To compare like with like. Thirteen periods of 28 days cover 364 days and each holds exactly four weekends, whereas a calendar month holds four or five depending on where the dates fall. Retail and UK payroll use this split, often in a 4-4-5 pattern so that the periods still add up to quarters. The odd day or two is absorbed by a fifth week added every five or six years.