This article is worth reading in order to understand the difference between Q and bandwidth when it comes to filter width.
rane.com – Bandwidth in Octaves Versus Q in Bandpass filters
Here is a PDF of the same information:
Rane – Bandwidth in Octaves Versus Q in Bandpass filters PDF
Here are wiki explanations of “Q factor” / “Quality factor” & Bandwidth
WIKI – Q factor
WIKI – Bandwidth (signal processing)
Here is a screen shot of the Rane table for those who want something portable:
