We have found 2 software records in our database eligible for .xls to .numbers file format conversion.
Microsoft Excel workbook (.xls) files can be opened and saved as Numbers spreadsheets (.numbers) only in the Numbers app for either Mac, iOS or iCloud.
If you have access to Numbers, simply open .xls file in the Numbers and save it again as the default .numbers spreadsheet using the File ► Save as function.
Users without Mac can still generate .numbers file directly from iCloud, because it offers web based iWorks apps that are more than enough for a simple xls to numbers conversion.
XLS
Files with xls extension are best known as spreadsheets from Microsoft Excel. A spreadsheet is basically a grid of cells sorted in rows and columns. Each cell can contain text, numeric or formula data. Excel XLS spreadsheets can be opened in most other similar programs, such as OpenOffice.org Calc.
NUMBERS
Files with numbers extension can be traditionally found in a spreadsheet format of Apple Numbers application on Mac OS X (macOS), iOS, and as a web service. Numbers spreadsheets can only be opened in the Numbers app; no 3rd party program can open or convert it to another format.