Calculation Issues

Calculate Invoice Age in Days with an Excel Date Formula

Khadija Khan Nov 13, 2026 868 views

Question details

The user needs to calculate how many days an invoice has been outstanding by comparing its invoice date with today's date.

Calculate Invoice Age in Days with an Excel Date Formula

Product: WPS Spreadsheets
Device & OS: not provided
Scenario: The user wants a formula that returns the number of days between an invoice date and the current date.
Observed behavior: The formula should return a positive age when the invoice date is in the past.

Before you start

Make sure the invoice dates are entered as valid Excel dates, and set the result cell format to General or Number before entering the formula.

Solution 1Recommended

Calculate Invoice Age with =TODAY()-C5 and Format as Number

Use this solution when the invoice date is in a cell such as C5 and you want the result to display as a number of days.

Excel stores dates as serial numbers, so subtracting the invoice date from today's date returns the number of days between them.

Select the result cell

Click the cell where you want the invoice age to appear, for example D5.

Enter the date subtraction formula

Type =TODAY()-C5 and press Enter, replacing C5 with the cell that contains the invoice date.

Fix the result format

On the Home tab, open the Number Format drop-down and select General or Number so the result displays as days instead of a date.

Calculate Invoice Age with =TODAY()-C5 and Format as Number

Result is a positive number: If the invoice date is in the past, the formula returns a positive number showing the invoice age in days.

Direct solution

Calculate Invoice Age in WPS Office Spreadsheets

Use the =TODAY()-C5 date formula in WPS Spreadsheets to quickly calculate how many days an invoice has been outstanding, then format the result as a number for clear reporting.

1. Open WPS Spreadsheets: Launch WPS Office and open the workbook that contains your invoice dates.
2. Select the age cell: Click the cell where you want the invoice age result to appear.
3. Enter the TODAY formula: Type =TODAY()-C5, replacing C5 with your invoice date cell, and press Enter.
4. Format the result: On the Home tab, choose Number or General from the number format menu so the result shows days.

Uses the same Excel-compatible TODAY function and date subtractionFull compatibility with .xlsx and .xls invoice workbooksFree and lightweight Office suite with familiar spreadsheet toolsEasy migration from Microsoft Excel without losing date formulasBuilt-in number formatting to display invoice age correctly

microsoft office alternative - wps office

Frequently Asked Questions

Why does my invoice age show as a date instead of a number?

The result cell is likely formatted as a Date. Select the cell, go to Home > Number Format, and choose General or Number.

Can I calculate invoice age if the invoice date is in the future?

Yes. The formula =TODAY()-C5 returns a negative number when the invoice date is later than today's date.

Does WPS Spreadsheets support the TODAY function?

Yes. WPS Spreadsheets supports Excel-compatible date functions, including TODAY() and direct cell subtraction.

How do I make the invoice age update automatically each day?

The TODAY() function is volatile and recalculates when the workbook opens or recalculates, so the age updates automatically.

Excel & Data Problems