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

  1. Select Operation: Choose Add Weeks, Subtract Weeks, or Weeks Between using the radio buttons at the top. By default it is selected Weeks Between.
  2. 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.
  3. Dates: All date fields are editable, click on and use the date picker or type a date in `YYYY-MM-DD` format.
  4. Calculate: Click the Calculate button to perform the calculation and see the results. .
  5. Results:
    • The main result is displayed in a large font.
    • The descriptive sentence below provides more context about weeks calculation.
  6. 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:

Weeks = (End Date − Start Date) ÷ 7

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.