What is Fretboard Radius and How to Choose the Right Size

Published Categorized as Guitar Information

Well, what is fretboard radius? How does it affect playability? And what can we do to help it?

All this and more today as we explore fretboard radius in undying detail.

Introduction to Fretboard Radius

One of the first things you notice when you grab a guitar neck is the rounded shape, which accommodates the natural curve of your hand. You’ll also notice that the shape of the back of the neck, where your palm fits, is different than the front of the neck — the fingerboard. Typically, the fingerboard side is flatter, but it has a convex arc. The shape of that arc is the fingerboard radius (sometimes called fretboard radius).

The fingerboard radius is the curvature of the fingerboard across the neck, from the lowest string to the highest string, and just like the radius of a circle, it can be described by a number.

The exact shape of that arc, from rounder to flatter, is expressed numerically in inches or millimeters. For example, if you’ve ever seen the specs for an electric guitar neck, you might have read 7.25-inch as the radius.

The way that number is derived is by drawing a circle with a 7.25-inch radius — remember, “radius” is a straight line from the center to the circumference of a circle — and placing the fingerboard at the top of the circle. The arc from one edge of the fingerboard to the other edge creates the 7.25-inch fingerboard radius.

Types of Fretboard Radius

There are typically three different types of fretboard radius to choose from:

Round (7.25 inches to 9.5 inches)

Ultimately, a tighter radius is more fitting to the natural ergonomics of your hand. That’s why rhythm- and chord-oriented players sometimes prefer the more pronounced arc of a rounder radius – it’s simply more comfortable to bend your hand and fingers around the curve when chunking out cowboy chords and multiple-finger barre-chord shapes.

Some believe that an old-school 7.25-inch-radius fingerboard chokes out when you bend on the higher frets. This is, however, more indicative of a poor setup than anything else. With the right skills, a 7.25-inch fingerboard can be set up to play just as easily and buzz-free as a more modern radius. After all, every Fender-slinging guitarist from the pre-1980s era cut their classics on a 7.25-inch radius!

Flat (16 inches and up)

These radii are at the other end of the spectrum, found primarily on Gibson-style guitars and pointy, shred-oriented axes. Generally, people like flatter radii for shredding because they don’t have to go over a hill and back down a hill to get to their spot.

Imagine that a guitar’s frets are shaped like a mountain peak with a high triangular point in the center. That would require significantly more hand movement since you must go up and over the peak to travel from the low E string to the high E string.

That nightmarish setup is an exaggerated version of the hill described earlier and found on tightly radiused fingerboards. Quick movements are critical for shredders; and, since a rounder radius requires more movement from your hand, a flatter radius will almost always be preferred by guitarists who value speed and efficiency over all else, no matter how minute the difference may be.

Medium (9.5 inches to 16 inches)

Many modern manufacturers now prefer to strike this sweet spot.

Current Fenders usually have a 9.5-inch radius, Gibson sticks with their trusty 12-inch radius, and PRS blurs them together with a 10-inch radius.

For most players sticking within these boundaries, the difference isn’t drastic. Give, for example, a 10-inch-radiused guitar to a guitarist who generally plays on a 9.5-inch radius, and it’s unlikely they’ll even be able to tell you which is which.

If you’d rather split the difference, then modern compound-radius fingerboards provide a rounder radius on the lower frets (near the nut) and flatten out on the higher frets for more effortless bends and faster movement.

Impact of Fretboard Radius on Playability

While the fretboard radius doesn’t make a difference in the guitar sound in real life, it does make a difference in the way you play the guitar. It’s not easy to find the general rule of thumb in this case, but there are several factors you can take into account when picking the right fingerboard radius.

The first factor is the curvature itself, which can affect your particular style in play (more on that later). The main things to consider are the difference in laying bars for bar chords as well as string bending.

The second factor you should pay attention to is how the strings are laid out. The distance between the fretboard and the string (or the action) can be either adjusted to the same distance across strings or with slight changes depending on the string. This is adjusted through the guitar bridge during manufacturing.

Some players like their strings near the frets to press them more responsively and with less effort. Others like to have their strings a tiny bit higher to lock in their positions and minimize failed notes during playing.

The combination of these two factors will combine with the third one, the player. The hand size, finger length, pressing strength, and the way a player holds the guitar neck will combine with the fretboard curvature and string action to form harmony or the lack of it when playing the instrument.

Choosing the Right Fretboard Radius

It isn’t a simple case of ‘bigger is better’ or vice versa: it all depends on your play style and what you’re looking to get out of your guitar.

Of course, your handspan and natural dexterity are worth considering, though the latter can be improved by practicing.

The most common sizes you’ll find on the market are 9.5”, 7.25” and 12”, but the key distinctions are usually broken down into two schools of thought:

A smaller radius and, therefore, a more rounded fingerboard, tends to better suit the natural curve of your fingers.

The best example is the 7.25”, which was the most popular size across a number of brands for many years and is now the defining feature of Fender’s Vintage style collection. This kind of specification is great for playing in lower neck positions, standard shapes, as well as a great range of barre chords.

One of the reasons why this size was so popular in the period between the 1950s and 80s was because it suited rhythm guitar, which was the predominant force in music before musicians started to refine more intricate styles.

On a very rounded radius, however, notes sometimes ‘choke out’ when you bend them because of the more pronounced ‘hump’ in the middle of the fretboard.

On the other hand, a flatter radius gives a more even playing surface, which is great for string bending and shifting vertically across the fingerboard with as much ease as possible, especially in higher positions on the neck.

Naturally, this makes the bigger radius popular among those playing lead guitar – a good example is the classic Gibson Les Paul, which comes with a 12” fretboard as standard and is played by the likes of Jimmy Page, Slash, and early Eric Clapton, among others.

If you play a scalloped fretboard, differences in neck radius have less of an impact.

Custom Fretboard Radii and Guitar Customization

Before you go ahead and get a luthier to help you customize your fretboard radius, here’s a whole list of different radiuses utilized by Fender and Gibson that you might call upon in your quest.

FenderEric Johnson12″12
FenderRedondo Special15.75″16
Froggy BottomMost20″20 (requires 20″ kit)
GibsonJ-4516″ or 12″16 or 12
GibsonLes Paul Standard 2013Compound 10″-16″10/16
GibsonVintage Les Paul12″12

Common Myths and Misconceptions About Fretboard Radius

The electric guitar is really the only stringed instrument that offers multiple fretboard radius options.

Classical guitars traditionally have no radius whatsoever. Martin acoustic guitars have had a 16-inch radius dating back to the 1930s. Electric basses have some variety, but it’s not a feature that is called out.

If you take a straw poll and ask your bass player friends what their favorite fingerboard radius is, you’re likely to get an answer like, “the one that’s on my favorite bass.” No, that’s not a bass-player joke; it just drives home the fact that fingerboard radius is the electric guitarist’s domain.

Conclusion: The Role of Fretboard Radius in Guitar Mastery

The most important thing to remember about fingerboard radius is that it is one aspect of many that contributes to the overall feel of a guitar.

Some prefer a radius that falls in the middle of the standard list, 9.5-inch – 10-inch, but others have been surprised by guitars with a flatter or rounder radius. The overall design of a guitar creates its feel and radius is just one component. Whatever radius feels right is the right radius for you.

Hopefully, you have learned something about what you prefer in a fretboard radius and how you can go about getting it.

FAQs What is Fretboard Radius

What is a good fretboard radius?

Most prevalent is the modern 9.5” radius (241mm), which was adopted in the 1980s and is now found on about two-thirds of Fender electric instruments. The next most common fingerboard radius, 7.25” (184mm), is a vintage-era spec now used on just under a third of Fender electric instruments.

Is a 9.5 or 12 fretboard radius better for small hands?

People with small hands tend to have an easier time playing on flatter, thinner necks, which means that they will often benefit from a fretboard radius that is 12“ or above.

How does fretboard radius affect playing?

As a general rule, a more curved fretboard tends to be a bit more comfortable for barring or chording than a flatter one.

By Nate Pallesen

Nate is just your average (above average) guitar player. He's no Joe Satriani, Jimi Hendrix or Jimmy Page - wait this site is about acoustic guitars (sorry) He's no Django Reinhardt, Chet Atkins, or Michael Hedges, wait? who!? He's no Robert Johnson, Eric Clapton or Ben Harper - more familiar? Anyway you get the point :-)

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