It can be maddening having lots of threads. Tou may think you have that particular thread, but are you sure? Without an inventory, it can be hard. You could make your own, but that is lots of writing.
Happily two stitchers, Susan Thompson and Linda Reinmiller have created spreadsheets for a ton of threads and are making them freely available to stitchers.
Linda also has links to conversion charts and plans to be adding more sheets in the future.
Find them here.