Excel's NETWORKDAYS formula counts the number of working days between two dates, automatically including both endpoints when they fall on weekdays and dropping every Saturday and Sunday from the total. The syntax is =NETWORKDAYS(start_date, end_date, [holidays]), where the optional third argument is a list of dates to subtract from the count. Used this way, the formula answers the everyday question "how many business days between these two dates" in a single cell, so it has become the standard Excel solution for project deadlines, payroll runs, shipping windows, and SLA turnaround times. NETWORKDAYS is inclusive: Monday to Friday of the same week returns 5, and a single weekday selected on its own returns 1. If you also need to handle custom weekend patterns (such as a Friday-Saturday weekend in the Middle East), Excel provides NETWORKDAYS.INTL with the same shape but an extra argument for the weekend pattern. For people who do not want to type a formula, assemble a holiday list, or open a spreadsheet at all, the same calculation runs in a browser with the Business Days Calculator, which mirrors NETWORKDAYS' inclusive behavior and optional holiday list while returning the answer instantly with no setup.
How Excel's NETWORKDAYS Formula Works
The formula behind nearly every Excel business-day calculation is NETWORKDAYS, a built-in date function that has shipped with Excel for decades. It takes two required arguments and one optional one:
- start_date — the first day of the period you want to measure. It can be a date in a cell, a date typed directly into the formula, or the result of another function such as DATE(2024,1,1).
- end_date — the last day of the period. The function never assumes a default; you must provide both endpoints.
- holidays (optional) — a range of dates that should be removed from the working-day count, such as a list of public holidays stored in a separate column.
What NETWORKDAYS does internally is exactly what the Business Days Calculator does in your browser: it counts the number of weekdays between the two endpoints, then subtracts any holidays that fall on weekdays. Unlike a plain =B2-A2 subtraction, which returns the total number of calendar days, NETWORKDAYS gives you the number of days actual work happens.
The output is always an integer. Excel also returns a #NUM! error if the start date is later than the end date, so the formula is sensitive to argument order. If you want to swap them without an error, wrap the result in ABS() or reverse the inputs.
Building the Formula in a Real Workbook
Here is a minimal end-to-end workflow that works in Excel 2016, Excel 2019, Excel 2021, Excel 365, and Excel for Mac.
- Type your dates into cells. Put the start date in cell A2 and the end date in cell B2. Format both as dates (Home → Number → Short Date) so Excel recognizes them as serial numbers rather than text.
- Enter the formula in an empty cell. Click into any other cell and type =NETWORKDAYS(A2, B2). Press Enter. The cell now displays the working-day count between the two dates, with weekends already excluded.
- Add a holiday list if you need one. In a new column, list any holidays you want to exclude as actual dates, not text. For example, put 2024-01-01 in C2, 2024-07-04 in C3, and 2024-12-25 in C4.
- Extend the formula to subtract the holidays. Change the formula to =NETWORKDAYS(A2, B2, C2:C4). Each listed date that falls inside your range and lands on a weekday is removed from the count.
- Press Enter and read the result. The cell now shows the working-day count after weekends and holidays are removed.
To see how the formula behaves, take a simple worked example: count the business days between Monday, January 1, 2024 and Monday, January 15, 2024. With no holidays entered, the formula =NETWORKDAYS(DATE(2024,1,1), DATE(2024,1,15)) returns 11. The reasoning is mechanical: the 15 calendar days contain two full weeks (each contributing exactly 5 weekdays, for 10) plus the leftover Monday at the end of the period (which contributes 1 more), giving 5 + 5 + 1 = 11 business days. The browser tool produces the same number for the same input.
When NETWORKDAYS Falls Short
NETWORKDAYS is the right tool for most English-speaking workweeks, but it has three practical limits that surface quickly in real projects.
- It assumes Saturday and Sunday are weekends. If your business works a Friday-Saturday or Sunday-Thursday schedule, you need NETWORKDAYS.INTL with an explicit weekend mask instead.
- It cannot subtract partial days. Half-days, observed holidays that fall on a Saturday but are taken on Friday, and shift work all require you to massage the formula by hand or layer another function on top.
- It trusts the holiday list you give it. A typo, a date in the wrong format, or a duplicate holiday will silently skew the count. Dates that fall on a weekend are gracefully ignored, but a date listed as the text string "2024-01-01" rather than a real date will be treated as a serial number and shift the entire result by tens of thousands of days.
The first limit is the one that forces most users to switch over to NETWORKDAYS.INTL. The second and third are the reasons people often reach for a separate tool instead of another formula.
Skip the Spreadsheet with the Business Days Calculator
For a quick answer that needs no setup, paste two dates into the Business Days Calculator and read the working-day count. The tool counts the same way NETWORKDAYS does — inclusively, weekend days removed — so anything that works in Excel will produce the same number in the browser. Three steps cover the entire workflow:
- Pick your start date. The calculator defaults to today, so change it to the day your period begins.
- Pick your end date. The business-day count, total days, and weekend days update instantly, with no button to press.
- Add holidays if you need them. Paste a comma-separated list of YYYY-MM-DD dates into the optional holidays field. Each qualifying date is removed from the working-day total; a holiday on a Saturday or Sunday is ignored, and duplicate dates are subtracted only once.
Everything runs on your device, so the dates never leave the browser. That makes the tool a clean fit for HR data, payroll periods, and contract dates that you would rather not paste into a third-party spreadsheet.
Excel vs. the Business Days Calculator
Both routes arrive at the same inclusive weekday count, but they trade off differently.
| Capability | Excel NETWORKDAYS | Business Days Calculator |
|---|---|---|
| Counts weekdays Monday to Friday | Yes | Yes |
| Includes both endpoints | Yes | Yes |
| Subtracts a holiday list | Yes (as a cell range) | Yes (comma-separated YYYY-MM-DD) |
| Custom weekend pattern | Only with NETWORKDAYS.INTL | No (Mon–Fri only) |
| Shows total calendar days | No (requires a separate formula) | Yes |
| Shows weekend days removed | No (requires a separate formula) | Yes |
| Needs Excel installed | Yes | No |
| Updates as you type | Only after pressing Enter | Yes |
| Data leaves your device | Only if the file is shared | No |
Pick Excel when the count is part of a larger model that depends on other cells, when you need NETWORKDAYS.INTL's custom weekend pattern, or when you are working with a workbook other people already share. Pick the browser tool when you need a single number you can trust without opening a spreadsheet, especially when the answer is going into an email or a ticket rather than a cell.
Edge Cases That Trip People Up
Most wrong answers come from one of four boundary conditions. Each one is worth checking before you commit the number to a deadline or a payroll run.
- Same start and end date. A single weekday returns 1 business day, not 0, because NETWORKDAYS counts inclusively. A single weekend day returns 0.
- Reversed dates. If start_date is later than end_date, Excel returns a negative number. The browser calculator handles this the same way, so swap the dates if you see a negative value.
- Leap day. February 29 is treated as an ordinary weekday whenever it falls on Monday through Friday. The full-weeks-plus-remainder approach used by NETWORKDAYS and the browser tool is exact across leap years, so the answer does not need any special handling.
- Holiday on a weekend. A public holiday listed for a Saturday or Sunday is ignored, because that day was never a working day. Both tools apply the same rule.
For readers who need the inverse calculation — landing on a date that is N business days from a starting point — pair the workflow with the Date Add Subtract Calculator to add or subtract whole days, then cross-check the result against the business-day count.
If you're weighing options, Add Days to Any Date with Calendar-Accurate Results covers this in detail.