The width of a guitar neck is measured at the nut, which is the small bone or plastic piece at the top of the neck where the strings are attached. The standard nut width for most electric guitars is 1.65 inches (42 mm), while the standard nut width for most acoustic guitars is 1.75 inches (44 mm).
Slim neck guitars typically have a nut width of around 1.5 inches (38 mm) or less. This makes the neck feel narrower and easier to wrap the hand around, which can be especially beneficial for players with small hands or who have difficulty reaching the higher frets on a standard guitar.
Some of the most popular slim neck guitars include the Fender Stratocaster, the Gibson Les Paul Junior, and the Ibanez RG series. These guitars are known for their fast necks and playability, making them ideal for a variety of genres of music, including rock, blues, and metal.
If you are looking for a guitar that is easy to play and has a fast neck, then a slim neck guitar may be the right choice for you. These guitars are available in a variety of styles and prices, so you can find one that fits your needs and budget.