How Does Scale Length Affect a Guitar’s Sound and Playability?

When choosing a classical guitar, we often focus on tonewoods, body construction, and tonal character. However, one of the most important factors influencing both sound and playability is scale length.

So, what are the differences between 650 mm, 660 mm, and 700 mm scale lengths?

What Is Scale Length?

Scale length is the vibrating length of a guitar string, measured from the nut to the saddle.

The most common scale length for classical guitars is 650 mm, although longer scales, such as 660 mm, are also used. Baritone guitars may feature longer scale lengths, such as 700 mm, to accommodate lower tunings.

Even small differences in scale length can affect string tension and the overall playing feel.

How Does Scale Length Affect String Tension?

When using the same type of strings and the same tuning, increasing the scale length increases string tension. Conversely, a shorter scale length results in lower string tension.

For example, a guitar with a 660 mm scale length will have slightly higher string tension than a 650 mm guitar when both use identical strings and are tuned to the same pitches.

However, string tension is not determined by scale length alone. String characteristics and tuning also play important roles.

In baritone guitars, a longer scale length helps maintain suitable string tension at lower tunings.

Comparing 650 mm, 660 mm, and 700 mm Scale Lengths

650 mm – Traditional Classical Guitar

The 650 mm scale is widely considered the standard for classical guitars. It offers a familiar playing feel and is a comfortable choice for many guitarists.

660 mm – Extended Classical Guitar Scale

A 660 mm scale produces slightly higher string tension than a 650 mm scale when using the same strings and tuning. The distance between frets also increases slightly.

These differences may be beneficial for some musicians, while others may prefer the feel of a shorter scale.

700 mm – Baritone Guitar

A 700 mm scale length can be particularly suitable for baritone guitar designs. The longer vibrating string length helps achieve appropriate string tension when using lower tunings.

However, a 700 mm scale does not automatically mean a louder or better-sounding guitar. The tonal result must be considered alongside the instrument’s overall design and string selection.

Does Scale Length Affect Tone?

Yes, scale length can influence a guitar’s tonal character. String tension, vibration characteristics, and the way the strings respond to the player’s touch all contribute to this relationship.

However, a longer scale does not necessarily mean greater volume, longer sustain, or better tone.

The soundboard, body construction, materials, and building techniques also play significant roles in shaping the instrument’s sound.

My Approach to Scale Length as a Luthier

At Can Oral Guitars, I consider scale length to be more than just a technical measurement. I believe it should be chosen according to the musician’s playing style, preferred tuning, and expectations from the instrument.

While 650 mm and 660 mm scales offer different playing characteristics for classical guitars, I use a 700 mm scale length in my baritone guitar designs.

For me, the key is to consider scale length as part of the guitar’s overall design, finding the right balance between tonal character and playing comfort.

Conclusion: Which Scale Length Should You Choose?

The 650 mm, 660 mm, and 700 mm scale lengths each serve different musical needs.

The right choice depends on your playing technique, physical comfort, preferred tuning, and musical expectations.

The best scale length is not simply the one that works technically, but the one that allows the musician to feel most comfortable and expressive.