We have found 6 software records in our database eligible for .ods to .xlsx file format conversion.
A typical ods to xlsx conversion basically represents saving spreadsheets from OpenDocument format (.ods) to Microsoft Excel 2007 and later format (.xlsx), something that can be nowadays done using any modern spreadsheet editor.
Open .ods file in Microsoft Excel or in any other similar program and use the File ► Save as .. menu to produce Excel workbook.
You may also find plenty of converters for this, but simple re-saves usually much more easier unless you do not have access to any spreadsheet editor.
ODS
Files with ods file extension can be nowadays commonly found as spreadsheets saved using Calc program from OpenOffice.org, LibreOffice and perhaps other office productivity bundles that use documents based on OpenDocument Format schema.
XLSX
Files with xlsx extension are s used by Microsoft Excel for its workbooks (spreadsheets) in Office Open XML format. XLSX is the latest spreadsheet format used by Excel with the adoption of XML formatting first used in Office 2007. While older xls files were in proprietary binary file format, xlsx spreadsheets use a somewhat altered XML scheme.