Please copy and use my bottle volume calculator. This is one of those times that the spreadsheet skills I often teach can be put to a very practical use.
I have been homebrewing for a few years now, and I like to bottle my homebrew using glass bottles that I collect from wherever I can get them. One of the drawbacks of reusing bottles is that I now have many sizes of bottles, with five different volumes. The last time I brewed I calculated the number I needed in my head, and ended up sterilizing about a dozen extra bottles. This time I decided to wash the exact number of bottles I needed (plus one, just in case). I calculated the number of bottles by creating this simple spreadsheet to figure things out for me.