Posted November 20, 2013 by James in Blog

Guitar frets. What does Medium Jumbo actually mean?

Fret anatomy


retwire is probably one of the least understood parts of a guitar in terms of its impact on play-ability.  “Frets are frets” couldn’t be further from the truth, so this short post will cover a little about frets, focusing in particular on “medium jumbo” frets, which are very common and have a name that sounds like part marketing jargon and part contradiction. By the end of this post, you should understand more about fret terminology and maybe what these mysterious medium jumbo frets actually are.

If you’re in the market to buy fretwire, scroll to the bottom of this post or click here.

When I say frets, I’m talking about the little wire strip across the neck that the string touches, not the gaps inbetween, where your finger depresses.  Frets are made from wire, usually a nickel alloy, though some frets are made of stainless steel.  The diagram above shows the anatomy of a fret, which will introduce some useful terminology.  We’re predominantly concerned with the width and the height, but I’ve also shown the parts of the fret that are embedded in the fretboard, the tang and the barb.  On some guitars, the tang is visible along the side of the fretboard, whereas some guitar builders conceal and/or trim the tang so that it doesn’t show.  The images below shows three examples of how fret tangs are shown (or not shown) on different guitars.

Comparing apples & oranges

“frets are frets” couldn’t be further from the truth

For starters, the main problem with fret sizes is that there is no strict standard to fret naming or sizing.  Some manufacturers use codes to identify their frets, Dunlop introduced codes like 6105 or 6130 which have become common to refer to a specific size (width and height).  However other manufacturers use words like “tall”, “jumbo”, “wide” or “slim” to describe their frets. The result is usually a lot of confusion and you’ll find many forum threads with people trying to make sense of it all.

The inescapable fact is that frets have two key dimensions, height and width.  Fret profile/shape is a third consideration, however we will be focusing on width and height.


Fret width is self explanatory, simply how wide it is. Measurements usually range from 1mm to 3mm (0.047″ – 0.118″)

  • Wider frets will often feel smooth as you slide over them going up and down the fretboard, however they can sometimes give an impression that there is less room inbetween to hit notes.
  • Thinner frets can sometimes feel like there are speed bumps on your fretboard, but they also feel less bulky.


Fret height pretty clearly means how high the fret wire stands off the fret board.  Heights range anywhere from 0.7mm up to 1.48mm (0.029″ – 0.058″) and I’m sure you can find more extreme examples out there (if so, leave a link in the comments).

  • Higher frets are usually easier for fast playing as there is little to no friction with your fingers hitting the fretboard.  Extreme examples of this are on guitars used by the likes of Yngwie Malmsteen who uses tall frets combined with a scalloped fretboard.  This is a really unusual feel if you’re not used to it, but if you have aspirations to play superfast, it could make things easier.  String bending is also more comfortable with higher frets.  

    Scalloped fretboard

  • The downside of higher frets are that pressing firmly on a note can actually make the note sound sharp as your finger pushes all the way down to the fretboard.
  • Lower frets can be harder to play fast because there is more friction with the fretboard, though you won’t have any issues with notes sounding sharp as you press hard.

What about medium jumbo?

If you’re not lost yet, you will be shortly.

Medium Jumbo is an attempt to give the fret size an easier to digest label, rather than a code.  However, thanks to the lack of a standard, the term “medium jumbo” just adds confusion.  To make matters worse, it looks to me that the term is backwards anyway.  Fret dimensions are written as width x height, however, considering most medium jumbo frets measure around 2.7mm x 0.91mm (0.106″ x 0.036″), it looks as though this is the wrong way around.  By looking at the ranges I listed above for both height and width, we see that 2.7mm is toward the top of the range for width, indicating that is the “jumbo” part of the name.  0.91mm is roughly in the middle of the range for height, indicating that this is the “medium” part of the name.  

So why isn’t aren’t they called “jumbo medium”?  To make matters even worse, “medium” and “jumbo” mean different things to different manufacturers!

Stick to the facts

So for me, to avoid all confusion, I recommend that you be aware of the actual dimensions if you are making choices based on fret size.  eg. if you have a Fender Telecaster with Medium Jumbo frets and want to purchase an ESP Eclipse with the same fret size, be aware that they use a different naming method.  If you can find out the actual fret size, you’ll be able to compare apples with apples.

be aware of the actual dimensions

Hopefully the post above answers a few questions about frets.  As I’ve suggested, forget the marketing naming and focus on width and height.  Mostly this isn’t really a factor unless you’re re-fretting a guitar. If you’re buying new, you’ll hopefully be trying the guitar out anyway and you can choose what feels the best for you.

Buying Fretwire

If you’re looking to replace your fretwire, as part of a guitar build or repairs, here are some useful links.


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