Open Calc file in MS Office

If I create a spreadsheet in Calc and send it via email, can the recipient open it in MS Office? I have Excel 2011 for Mac that won’t open it. I need to send a Calc file to a recipient who uses an unknown version of Excel. I am looking for a substitute for the 32-bit Excel for Mac that won’t work after the next macOS upgrade. I thought Libre might be a good option.

The native format for spreadsheets in LibreOffice is .ods and it is recommended that you always save your work in the native format. But to send a copy of your spreadsheet to someone else who uses Excel, you could save a copy of your work in .xls (Excel) format (use menu File → Save As) and send that to him.

For exchanging data files, I think it does not matter whether the operating system is 32- or 64-bit, though I could be wrong in special circumstances.