Weeks Calculator: Add, Subtract, Between Dates
To use weeks calculator, choose any option, such as adding or subtracting weeks to a specific date, or seeing the number of weeks between two dates.
For example, adding 4 weeks to January 1, 2025, will give you January 29, 2025. Subtracting 3 weeks from March 10, 2025, will give you February 17, 2025. To find the number of weeks between May 1 and June 12, you will get 6 weeks.
1 week
There are 1 week and 0 days from July 4, 2025 to July 11, 2025.
Steps To Use the Weeks Calculator
- Select Operation: Choose Add Weeks, Subtract Weeks, or Weeks Between using the radio
buttons at the top. By default it is selected Weeks Between.
- Enter Values:
- For Weeks Between: Select a Start Date and an End Date. The calculator will show you
the total weeks. The initial result is 1 week between two dates.
- For Add Weeks: Select a starting Date" and enter number of Weeks to add. The calculator
will show the future date.
- For Subtract Weeks: Select a starting Date and enter number of Weeks to subtract. The
calculator will show the past date.
- Dates: All date fields are editable, click on and use the date picker or type a
date in `YYYY-MM-DD` format.
- Calculate: Click the Calculate button to perform the calculation and see the results.
.
- Results:
- The main result is displayed in a large font.
- The descriptive sentence below provides more context about weeks calculation.
- Clear Button: Click Clear to reset all input fields and the result display to the default
Weeks Between calculation.
Note: The maximum number of weeks for addition or subtraction is
5220 (approximately 100 years). The calculations take into account different lengths of months
and leap years.
Weeks Between Dates Calculation:
To calculate the number of weeks between two dates, you can use the following formula:
- End Date: The later date.
- Start Date: The earlier date.
- Weeks: The total number of weeks between the two dates.
Weeks = (End Date − Start Date) ÷ 7
- Dates to Milliseconds: Subtract the start date from the end date to
find the difference in milliseconds.
- Milliseconds to Days: Divide the difference by 1000 × 60 × 60 × 24
to convert milisecond into days.
- Days to Weeks: Divide the total number of days by 7 to get the number of weeks.
Days = Difference ÷ (1000 × 60 × 60 × 24)
Then, Weeks = Days ÷ 7
This is how you can use the formula to calculate the number of weeks between two dates.