XLR is a file extension usd by Microsoft Works office suite. XLR is a spreadsheet document file structured similar to any standard spreadsheet documents.

XLR files store data in cells organized in rows and columns. Each cells has it own unique address. Cells can hold various types of data including numbers, strings, and formulas (functions that return value based in input). XLR files were used by Microsoft Works versions from 6 to 8. XLR files generated by version 8 of the software are also supported by Microsoft Excel.