Weeks Between Dates
Enter two dates to see how many weeks lie between them, with the leftover days and the exact total in days.
Last updated November 2, 2026
Defaults to today
Defaults to 90 days from today
Result
12 weeks and 6 days
90 days in total · 12.86 weeks
Show the work
- Days between November 12, 2026 and February 10, 2027: 90 days.
- Divide by 7 days in a week: 90 / 7.
- Whole weeks plus leftover days: 12 weeks and 6 days.
- As a decimal number of weeks: 12.86.
How weeks between dates are counted
weeks = whole 7-day blocks in (later date − earlier date)
leftover days = the remainder
The calculator counts the days between the two dates, divides by 7, and shows the whole weeks and the leftover days. The earlier date is day zero.
It also shows the decimal value (days ÷ 7), which is useful for pay periods and project plans. A week here is 7 calendar days, not a Monday-to-Sunday calendar week.
See how we calculate for the formulas, sources and review schedule behind every calculator.
Also useful alongside this calculator: Business Days Calculator and Date To Date Calculator.
Whole weeks, leftover days and decimal weeks
Dividing days by 7 gives a whole number of weeks and a remainder. 30 days is 4 weeks and 2 days, or 4.29 weeks. 90 days is 12 weeks and 6 days, or 12.86 weeks. 100 days is 14 weeks and 2 days, or 14.29 weeks. A full year is 52 weeks and 1 day (365 days) or 52 weeks and 2 days (366 days).
The decimal is the leftover days divided by 7 and then rounded, so it is slightly different from a count of whole weeks. Use the whole weeks and days to describe a gap in words, and the decimal when you need a single number for a calculation.
Project and pay-period planning
When the start and end dates fall on the same weekday, the gap is always a whole number of weeks. A project that starts on Monday, March 2, 2026 and ends on Monday, May 25, 2026 runs 84 days, which is exactly 12 weeks with no leftover days.
The same arithmetic explains why a biweekly payday schedule has 26 pay dates in most years and occasionally 27. A year is 52 weeks plus 1 or 2 days, so it holds slightly more than 26 two-week cycles, and the extra payday depends on where the first one falls.
Elapsed weeks versus calendar weeks
Wednesday, January 7 to Wednesday, January 21, 2026 is 14 days, which is 2 weeks. That span touches three calendar weeks running Monday to Sunday, because the two dates sit in different weeks. If you need to count calendar weeks, count the Mondays instead.
Counting both ends changes the total: January 5 to January 12 is 7 days, or 1 week, but 8 days if both dates are included. Add 1 day before dividing by 7 when you want that.
How to use the Weeks Between Dates
- Enter the start date.
- Enter the end date. The order does not matter.
- Read the whole weeks and leftover days, and the total in days and decimal weeks.
- Open "Show the work", or use Copy, Print or Share.
Worked example
From Monday, January 5, 2026 to Thursday, December 31, 2026 is 360 days. That is 51 weeks and 3 days, or 51.43 weeks. Working it through: 51 weeks is 357 days, which leaves 3 days. The decimal is 51 + 3 ÷ 7 = 51.4286, rounded to 51.43.
| Date | Days | Weeks and days |
|---|---|---|
| February 1, 2026 | 31 | 4 weeks 3 days |
| March 1, 2026 | 59 | 8 weeks 3 days |
| April 1, 2026 | 90 | 12 weeks 6 days |
| May 1, 2026 | 120 | 17 weeks 1 day |
| June 1, 2026 | 151 | 21 weeks 4 days |
| July 1, 2026 | 181 | 25 weeks 6 days |
| August 1, 2026 | 212 | 30 weeks 2 days |
| September 1, 2026 | 243 | 34 weeks 5 days |
| October 1, 2026 | 273 | 39 weeks 0 days |
| November 1, 2026 | 304 | 43 weeks 3 days |
| December 1, 2026 | 334 | 47 weeks 5 days |
Frequently asked questions
How many weeks are in a year?
A year has 52 weeks and 1 day, or 52 weeks and 2 days in a leap year, because 365 and 366 are not multiples of 7.
Does it use calendar weeks from Monday to Sunday?
No. It counts 7-day blocks between the two dates, whatever weekdays they fall on.
Why do I get a decimal such as 14.29?
The decimal is the total days divided by 7. 100 days is 14 weeks and 2 days, and 2 ÷ 7 is about 0.29, so the total is 14.29 weeks.
How do I include both the start and the end date?
The calculator treats the start date as day zero. Add 1 to the total days before dividing by 7 if you want both dates counted.
Are my dates stored or sent anywhere?
No. The calculation runs in your browser and nothing you enter is saved or uploaded.