How to Calculate Number of Days in Excel Including Start and End Date Easily

Calculating the number of days between two dates in Excel is a breeze once you know how. You simply need to enter your start and end dates, and then use a formula to find the difference. This guide will walk you through the process step-by-step, making it easy to follow along and understand.

How to Calculate Number of Days in Excel Including Start and End Date

This section breaks down the steps to help you calculate the number of days between two dates in Excel, including the start and end dates. By the end, you’ll have a handy formula to use whenever you need it.

Step 1: Open Excel and Enter Dates

First things first, open Excel and enter your start date in one cell and your end date in another.

For example, you might type your start date (e.g., 01/01/2023) into cell A1 and your end date (e.g., 01/10/2023) into cell B1.

Step 2: Click on a New Cell for the Formula

Next, click on a blank cell where you want the number of days to appear.

This could be any cell, such as C1, where the result will display.

Step 3: Enter the Formula

Now, type the formula: =B1-A1+1 in the cell you selected.

This formula calculates the difference between the two dates and adds 1 to include the start date.

Step 4: Press Enter

Press the Enter key to execute the formula.

After pressing Enter, Excel will display the number of days between your start and end dates in the selected cell.

Step 5: Check Your Result

Finally, check the result to ensure it matches your expected number of days.

For instance, if your start date is 01/01/2023 and your end date is 01/10/2023, the number should be 10.

After completing these steps, you’ll have the number of days between your two dates, including both the start and end dates.

Tips for Calculating Number of Days in Excel Including Start and End Date

  • Ensure that your dates are in a recognizable format like MM/DD/YYYY, so Excel can properly interpret them.
  • Double-check that your cells are formatted as dates; otherwise, the formula might not work correctly.
  • You can use similar formulas to calculate the difference in months or years by adjusting the formula.
  • Use the DATE function if you’re working with dynamic dates that change over time.
  • Keep in mind that Excel treats dates as serial numbers, so converting them to actual numbers can sometimes help in troubleshooting formula errors.

Frequently Asked Questions

How do I format cells as dates in Excel?

Right-click the cell, select "Format Cells," choose "Date," and pick a date format.

Can I calculate the number of business days between two dates?

Yes, use the NETWORKDAYS function instead of the basic subtraction formula.

How do I include weekends in my calculation?

The basic formula =B1-A1+1 includes weekends by default.

What if my dates are in text format?

Use the DATEVALUE function to convert text dates to Excel-recognized dates.

Can I calculate the difference in months or years?

Yes, you can use the DATEDIF function to calculate differences in months or years.


  1. Open Excel and enter dates.
  2. Click on a new cell for the formula.
  3. Enter the formula =B1-A1+1.
  4. Press Enter.
  5. Check your result.


Now that you’ve learned how to calculate the number of days in Excel, including the start and end date, you should find it much easier to handle date calculations in your spreadsheets. This skill is super handy for project management, scheduling, and even personal tasks like tracking the days until an event.

Remember, practice makes perfect. So, try out different date ranges and get comfortable with the formula. If you encounter any issues, refer back to the tips and FAQs sections for extra guidance. Happy Excel-ing!

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