This Javascript app converts a list of frequencies into a tab-delimited list of pitch classes (note name), with octave and cents deviation from 12TET, ready for copying and pasting into an Excel spreadsheet. It also draws them with music notation, and allows you to export to a MusicXML file.

(enter in Hz, one per line):

Tab-delimited for copying & pasting into Excel

Music Notation:

NB: quarter-flats and quarter-sharps are encoded as double-flats and double-sharps, as Sibelius does not correctly import quartertones. Grrrr.