Fretboard’s Radius #

Smaller radius means a more rounded shape.

• 7-1/4" – "Vintage" Fender®
• 9-1/2" – "Modern" Fender®
• 10" – Gibson®/PRS®
• 12" – Ibanez®
• 16" – Jackson®
• compound (10" – 16") – Warmoth® and others

youtube.com – understring radius gauges – video demonstration of three different gauges used for guitar setup and fretwork: standard, notched and understring.