The Guitar Scale Length Explained

What is Scale Length?

Also called string length, scale is defined on a guitar as the distance between the bridge and the nut or the maximum length of an opened string producing sound or vibrating freely, commonly measured in inches.

How To Measure Scale Length

There are two ways to measure when identifying the scale of your instrument.

1. Approximate &
2. Accurate

Approximate

It is a term used for measuring scale length from the nut to the bridge on the guitar as a single “approximate or general” measurement. (see Image)

This measurement is not entirely consistent or accurate, for based on which string you measure on the bridge; they are all slightly different scale lengths.

Compensation

This term describes adjustments of each string’s guitar saddle  (forward and back) needed to compensate for proper intonation across the entire fingerboard. (See Image)

How Compensation Works

Forward adjustments closer to the nut compensate for flat notes, whereas back adjustments prevent notes from ringing sharp.

What Is Intonation?

It is a term to describe the guitar’s “open” string tuning along with every fretboard note sounding at its correct pitch, as opposed to when the instrument is “out of tune with itself,” where you can tune the open strings and notes are always off-pitch on the fretboard.

Accurate Measurement

To get an accurate scale length, you can approach it in two ways…

1. Measure each string’s length and calculate the average – This is time-consuming and not recommended.
2. Measuring from the front edge of the nut, where it meets the end of the Fretboard to the middle/centre of the 12 Fret/Octave or where the string contacts the 12th fret when pressed down and then doubling the value – This is common and recommended by most luthiers. (See Image)

Common Scale lengths

The most common or standard guitar scale length is 24.75″ (628mm), found on most Gibson electric guitars & 25.5″ (648mm), which you will find on numerous Fender models.

The majority of other popular scale lengths will vary around these two standards.

Why Does Scale Length Matter?

Scale length fundamentally contributes to where the overtones or harmonics occur across each string, along with affecting the guitars…

• String Tension & Tones
• What String Gauges Are Used
• String Action &
• Fret Spacing 

What Are String Harmonics?

This is where the note harmonics are spaced on the string based on your guitar’s scale & tension.

The longer scale length will have an increased spacing of the string note harmonics, whereas a shorter scale will pack the harmonics closer together.

Scale/String Tension & Tones

String tension determines the range of tones the string can produce at a given tension.

When the scale length increases (25.5″ & up), the tension across the strings must increase in pressure to bring the guitar to the proper pitch.

When the scale length decreases (24.75″ & down), the strings will have less tension requiring less pressure to be brought to pitch.

Bright & Clear Tones

Longer scale lengths  (25.5 ” & up) result in bright, crisp & defined overtones and ensure low-end clarity compared to shorter scales which can sound muddier. (i.e. Fender Stratocasters /Telecasters & Baritone guitars with extra strings 7/8/9.)

Pros & Cons of Longer Scales

Pros

• More spaces between frets – For a more comfortable feel, accuracy and precision for larger fretting hands.
• More Tension– For a bright, snappy tone & lighter String gauges resulting in a firmer feel that is not too loose.
• It goes well with lower action setups without fret buzz (More on this later)
• Works well with drop tunings
• More travel distance up & down the fretboards

Cons

• Heavier gauge strings are harder to bend and fret press the notes
• Not the warmest tone
• Wider frets may be more uncomfortable for smaller fretting hand players

Full & Warm Tones

With shorter scale lengths with lower applied string tensions (24.75′ & down), the sound is thicker and warmer, less bright or crisp, with more sustain resulting from the lower tension allowing strings to vibrate more freely. (i.e. Les Pauls, SGs, Flying V, Explorer, SG, ES-335 and other Gibson-inspired guitars. )

Pros & Cons of Shorter Scales

Pros

• Frets are closer together – More for players with smaller fretting hands
• Strings have less tension – Good for heavier gauge strings and easier for bending, along with fret pressing the notes.
• Creates a warmer and fuller tone
• Less travel distance up & down the Fretboard
• Higher-tuned strings are going to sound better on shorter-scale length instruments.
• Lower string tension makes strings easier to press down

Cons

• Not the brightest or the most articulation in sound
• Can cause fret buzz with lower Action
• Drop tunings may be more problematic
• Smaller fret spacing might be harder to play for larger hands

Best of Both Worlds

 PRS 25″ Scale Length

PRS-created guitars fill the gap between the two standard scales offering crisp note definitions and fullness to get the best of both worlds.

Pioneering a 25″ (635mm) hybrid scale length, these guitars give a familiar feel and sound while creating something completely new.

The 25″ scale captures the harmonic richness of the Fender electrics and the fullness, warmth, and playability of the Gibson.

Scale/Tension & String Gauges

Since we know that scale length impacts the tension across your guitar strings, how can we easily adjust the tension in our strings using different string gauges.

Rule of Thumb

Generally, use a lighter string gauge to counteract the added tension created by the longer scale length and reduce the string tension on a guitar. (i.e. 25.5″ go with 9-42 gauge strings.)