Guitar Fret Sizes: Reading Measurements in Millimeters

Reading the two numbers in a fret spec

When a guitar listing shows fret dimensions, it gives two millimeters: crown width and crown height. Crown width is the horizontal measurement across the top of the fret, the part your string touches. Crown height is the vertical measurement from the fingerboard surface to the top of the crown. The two numbers together describe the physical size of the fret wire.

For example, a spec of 2.7 mm wide and 1.3 mm tall describes a medium-large profile. The first number, 2.7 mm, is the crown width; the second, 1.3 mm, is the crown height. A taller fret feels rounder under the fingers and sits further above the fingerboard, while a wider, flatter crown gives a more vintage feel. The same logic applies across all fret wire categories, from the smallest vintage-style wire to the largest modern jumbo profiles.

Some makers list only one number or use names such as medium, jumbo, or super jumbo. When only names are given, you can still compare relative size, but the millimeter values tell you exactly how much metal you are getting. If a spec sheet is silent, the safe assumption is a medium or medium-jumbo size, which is the most common on modern production guitars. You can also check fret wear and leveling to understand how these numbers change over time.

Why fret height matters for playability

Fret height is the dimension that most directly affects how the guitar feels. A taller fret lifts the string further above the fingerboard, which gives your fingertips more room before they touch the wood. This makes bending and vibrato easier, because the string is already suspended at a height where it can move laterally without your fingertip bottoming out on the fingerboard. If you are dealing with action and setup, fret height plays into how the guitar responds to your touch.

A shorter fret sits closer to a scalloped or historical feel. With low frets, you feel the fingerboard more under your fingers, which some players prefer for traditional blues, country, or folk playing. The trade-off is that bending requires more deliberate pressure and the fingertips can contact the wood sooner, which can slow you down during long lead lines.

Taller frets do ask for a slightly firmer grip shape and a lighter touch overall. If you developed your technique on low frets, going taller can feel strange for a week or two. Conversely, if you are used to tall frets, a low-fret guitar can feel sluggish. There is no right answer, only the feel you connect with.

• Tall frets: easier bending, easier vibrato, less fingerboard contact.
• Medium frets: balanced feel, good for varied styles.
• Low frets: vintage feel, more direct fingerboard contact, classic tone character.

Why width matters for tone and hand feel

Crown width affects the surface area the string sits on. A wider crown gives the string a broader contact patch, which some players describe as a fatter, more solid tone. It also spreads pressure over a larger area, which can reduce the chance of string wear creating grooves in the fret top over time.

A narrower crown feels more precise under the fingers. If you play with a light touch and want to feel the exact position of each fret, a narrow crown gives more immediate feedback. For slide playing, a wider crown can provide a smoother, more stable surface for the slide to travel across.

Width also interacts with the fretboard radius. On a curved fingerboard, a very wide crown has to be curved to match the board, otherwise the outer edges of the fret will sit slightly higher or lower than the center. Many builders use a compound radius precisely so that wider frets can stay consistent across the neck. If you are comparing two guitars, a wider crown on a round radius can feel different from the same wire on a flatter radius.

Stainless steel vs. nickel-silver fret wire

The material matters as much as the size. Traditional fret wire is nickel-silver, an alloy of nickel, copper, and zinc that contains no actual silver. It has a warm, smooth feel and is softer than stainless steel, which means it wears more quickly but is easier to dress and polish. Most vintage-style and acoustic guitars use nickel-silver wire.

Stainless steel frets last much longer, resist corrosion, and keep their crown shape longer under heavy bending. They also produce a slightly brighter attack, which some players enjoy for electric guitars. The main trade-offs are a harder feel under the fingers and more difficult leveling work when maintenance is needed. If you plan to keep a guitar for many years, stainless steel can save you from a fret replacement down the road. For a deeper comparison, see stainless steel frets vs. nickel-silver.

The decision between the two materials is separate from the size question. You can have tall wide stainless frets on a modern metal guitar, or short narrow nickel-silver frets on a vintage restring. Many players choose stainless for a daily player and nickel-silver for a traditional instrument where authentic feel is part of the experience.

How to measure fret dimensions yourself

If a spec sheet does not list fret sizes, you can measure them at home with a digital caliper. Place the caliper jaws across the crown width at the widest point, which is usually just above the fret ends. For height, measure from the fingerboard surface to the top of the crown, taking care not to include any glue or finish buildup at the base of the fret.

Measure the first few frets rather than the middle of the neck, because frets near the nut are usually the most consistent and least worn. If you are checking a used guitar, also compare the height on frets 1 through 5 against frets 10 through 15. A noticeable difference means the frets have wear and may need leveling or crowning. Knowing how to crown and recrown can help you assess the condition.

Measuring is useful when you want to match a replacement fret wire to the existing frets, or when you are comparing two guitars with identical specifications on paper. The measurement will tell you the crown size, but it will not tell you how the fret ends were filed, how well the fret sits in the slot, or whether the fingerboard was leveled before installation. Those installation details affect feel just as much as the wire dimensions.

Match fret size to your playing style

There is no universal rule that one fret size is best, but certain styles tend to pair well with certain profiles. Players who spend most of their time bending and doing wide vibrato on an electric guitar usually prefer a taller crown, because it gives more leverage and keeps the fingertips off the board. Players who play fingerstyle on an acoustic often prefer a medium or medium-low crown, because it keeps the string closer to the wood and makes the guitar feel more responsive to subtle finger pressure.

If you play a 7-string or 8-string guitar for metal and modern rock, you will likely encounter medium and jumbo wire more often. The extra strings mean a wider neck, and taller frets help you articulate each note cleanly at high gain. On the other side, a classical or nylon-string guitar uses no fret wire at all, with the strings directly over a tied bridge, so fret size is not a factor there.

For beginners, the most comfortable place to start is a medium profile. It is versatile enough for chords, single-note lines, and bending, and it does not exaggerate either the vintage or the modern feel. If you already know you like a particular fret size from a guitar you own, looking for a similar measurement in a new instrument is a practical way to narrow your search. Check the best electric guitars and best acoustic guitars for models that match what you are after.

What to pick for your use

Questions

How do I convert fret millimeters to inches?

Divide the millimeter value by 25.4. For example, a 2.7 mm crown width is about 0.106 inches, and a 1.3 mm height is about 0.051 inches. Most spec sheets now use millimeters, so conversion is rarely necessary unless you are comparing to an older catalog.

Can I change the fret size on my guitar?

Yes, a luthier can replace the frets with a different wire size. This involves pulling the old frets, dressing the fret slots, installing the new wire, and leveling and crowning the crowns. It is a significant job that affects the neck's feel and playability, so it is best done by an experienced technician. For a guide on the process, see how to replace a guitar fret.

Does a taller fret reduce fret buzz?

Taller frets can help in some cases because they raise the strings further from the fingerboard, giving you more room before the strings touch the next fret. However, buzz is usually caused by relief, nut height, or action issues, not the fret size alone. A proper setup and a straight neck matter more than crown height. You can learn more about action and setup.

Is fret width related to the fretboard radius?

Yes. The fret top is curved to match the fingerboard radius, so a wider crown on a round radius has a more pronounced curve. If the radius is very flat and the crown is very wide, the fret edges can feel slightly higher in the middle. Many modern guitars use a compound radius to make wide frets feel consistent across the neck. See fretboard radius for more.

Do stainless steel frets feel different from nickel-silver?

Yes, stainless steel has a harder, slightly slicker feel, while nickel-silver feels warmer and more traditional. Stainless steel also resists wear and corrosion better, but it is more difficult for a technician to level and polish if the frets become uneven. The difference is covered in stainless steel vs. nickel-silver.