The Percentage Calculator app for Office was designed to work in Word 2013 and Excel 2013. With an easy to use interface, you can select the percentage calculation of choice and insert the results into your documents.
Added to that is the ability to highlight a selected range of numbers in an Excel spreadsheet and add or subtract a percentage amount. This automatically inserts the converted values directly back into your Excel spreadsheet.
We expect the app to be live on the Office.com store pretty soon, so please stay tuned and we’ll update this page with more details as we receive it.
The app is now live on the Office Store!
Download it now at http://store.office.com/en-us/store/percentage-calculator-WA104047359.aspx
UPDATE: You can also use the free online Percentage Calculator here