Hello Vicki,
The manufacturer does not supply the dimensions for replacement glass pieces like this since they are made only to fit the exact fan that came with the glass originally. So if you have the Minka Aire Zen ceiling fan F514-BN or F514-WH, it will fit your fan. Otherwise, there is no sense in buying this particular glass shade because there is no way of knowing whether or not it will fit on any other fan, and most likely it will not.
Sorry, that's the best I can do.
