Understanding the real differences between low, medium, and high tension classical guitar strings
Walk into any music store or browse any string retailer and you'll find classical guitar strings labeled as low tension, normal tension, medium tension, hard tension, high tension, extra high tension—and sometimes with numeric ratings that seem to follow no standard at all. It's enough to make you grab whatever you bought last time and move on.
But string tension genuinely matters. The right tension for your guitar and your hands can make playing feel effortless. The wrong tension can leave you fighting the instrument, fatiguing quickly, or wondering why your guitar sounds dull when it used to sing. This guide will help you understand what tension actually means, how it affects playability and tone, and how to find the right match for your playing style.
What Does "Tension" Actually Mean?
String tension refers to the force required to bring a string up to pitch. A high-tension string needs more force to reach the correct frequency than a low-tension string of the same pitch. This force is measured in kilograms or pounds, and it's the sum of all six strings that creates the total tension on your guitar's top.
A typical set of normal-tension strings exerts somewhere around 38 to 42 kilograms of total force on the guitar. High-tension sets push that toward 42 to 46 kilograms. Low-tension sets might come in around 34 to 38 kilograms. These differences may seem small, but your fingers notice them immediately, and your guitar's top responds to them over time.
It's worth noting that there's no universal standard for tension labeling. One manufacturer's "medium" might be another's "hard." This is why experienced players often look at the actual tension numbers (when provided) rather than relying solely on descriptive labels.
Tension Labels vs. Actual Numbers
Manufacturers use different terminology for similar tensions. Here's a rough guide to how labels typically correspond:
Low / Light / Moderate: ~34–38 kg total
Normal / Medium: ~38–42 kg total
Hard / High: ~42–46 kg total
Extra Hard / Extra High: ~46+ kg total
When in doubt, check the manufacturer's specifications for actual tension values per string.
How Tension Affects Playability
The most immediate difference you'll feel between tensions is in your left hand. Higher tension strings require more finger pressure to fret cleanly. Lower tension strings need less pressure, which can reduce fatigue during long practice sessions or performances.
But it's not quite that simple. Lower tension also means the strings have more slack, which allows them to move more when plucked. This increased movement can cause buzzing if your action is set low, and it can make the strings feel "floppy" to players accustomed to more resistance. Some guitarists find this looseness liberating; others find it imprecise.
Higher tension strings feel tighter and more controlled under the fingers. They respond quickly and stay put, which some players prefer for fast scalar passages. But that tightness comes at a cost: more effort required from both hands, and potentially more strain over time if your technique relies on excessive force.
The best tension is the one that lets you play with relaxed hands while giving you the control and response you need. There's no universally "correct" answer.
For the right hand, tension affects how much energy you need to put into each stroke. High-tension strings can produce more volume with an aggressive attack, but they can also feel resistant if you prefer a lighter touch. Low-tension strings respond easily to gentle playing but may lack projection when you need power.
How Tension Affects Tone
The relationship between tension and tone is real but often overstated. Higher tension strings tend to produce a brighter, more focused sound with tighter bass response. Lower tension strings often sound warmer and rounder, with more overtones and a slightly looser bass.
However, your guitar's construction plays a far larger role in your overall tone than string tension does. A lightly built, responsive instrument might sound thin with low-tension strings or come alive with them, depending on the builder's intent. A heavily constructed guitar might need higher tension to drive the top effectively.
The interaction between string tension and your specific guitar is why experimentation matters more than generalizations. What sounds wonderful on your teacher's guitar might not suit yours at all.
Matching Tension to Your Guitar
Some guitars are built with a particular tension range in mind. Lightly braced, French-style instruments often respond best to lower tensions—the tops are designed to move freely, and too much tension can choke them or even cause structural problems over time. More heavily built Spanish-style guitars may need medium or high tension to really open up.
If you're not sure what your guitar prefers, start with medium tension. It's the safe middle ground that works reasonably well on most instruments. Then experiment: try a set of high tension and pay attention to whether the guitar sounds more alive or more constrained. Try low tension and notice whether you gain warmth and ease or lose clarity and punch.
Flamenco guitars present a special case. They're typically built with lower, faster action and lighter construction to facilitate the percussive techniques of flamenco playing. Many flamenco players prefer medium or even low tension strings to preserve the guitar's quick response and characteristic brightness. High tension can work, but it may slow down the guitar's attack and feel sluggish for rapid rasgueados.
Signs You Might Need Different Tension
Consider lower tension if: Your left hand fatigues quickly, you're getting excessive buzzing that requires raising action too high, or your guitar sounds choked and unresponsive.
Consider higher tension if: Strings feel too loose and imprecise, you want more volume and projection, or your guitar sounds muddy and unfocused in the bass.
Matching Tension to Your Playing Style
Beyond your guitar's preferences, your own playing style should guide your choice.
If you're a beginner or returning player: Start with low or normal tension. Your hands are still developing strength and coordination, and fighting stiff strings will slow your progress and potentially cause strain. You can always move up later as your technique matures.
If you have small hands or finger joint issues: Lower tension reduces the force needed to fret notes cleanly. Many players with arthritis or other joint concerns find that switching to low-tension strings extends their playing years significantly.
If you play with a heavy right-hand attack: Higher tension strings can handle aggressive playing without excessive buzzing or going sharp under pressure. They'll also project better in live settings where you need volume.
If you prioritize delicate, nuanced playing: Lower tension strings respond more easily to subtle dynamic variations. They reward a refined touch and can make pianissimo passages sing rather than disappear.
If you play a lot of barre chords: This is where tension becomes very personal. Some players find lower tension easier for barres because less pressure is needed. Others prefer higher tension because the strings don't deflect as much under the barre finger. Try both approaches.
Mixed Tension Sets
One approach that many professional players use is mixing tensions—for example, high-tension basses with normal-tension trebles, or vice versa. This lets you fine-tune the balance and feel of each register independently.
Why would you do this? The treble strings (nylon or carbon) and bass strings (wound metal over nylon or other cores) behave quite differently. You might find that high-tension trebles give you the clarity you want but high-tension basses feel too stiff. Or you might want powerful basses but more supple trebles for expressive vibrato.
Manufacturers like Knobloch make this easy by offering individual strings and clearly labeled tension options that are designed to be mixed. It takes some experimentation, but many players find their ideal setup is a combination rather than a matched set.
| Playing Priority | Suggested Starting Point |
|---|---|
| Ease and comfort | Low or normal tension |
| Volume and projection | High tension |
| Nuance and dynamics | Normal or low tension |
| Fast technical passages | Normal to high tension |
| Flamenco techniques | Normal tension (often) |
| Joint pain or fatigue | Low tension |
A Note on Carbon Trebles
Carbon (fluorocarbon) treble strings have become increasingly popular, and they behave somewhat differently than traditional nylon. Carbon strings are denser than nylon, so they're thinner at the same pitch and tension. This thinner diameter can make them feel different under the fingers—some players love the slick, fast feel, while others find them too thin.
Carbon trebles also tend to be brighter and louder than nylon, with longer sustain. If you switch from nylon to carbon trebles at the same tension, you may find the balance between treble and bass shifts noticeably. Some players compensate by using higher-tension basses with normal-tension carbon trebles, or by choosing a warmer-sounding bass string to offset the brightness.
The Only Way to Know: Experiment
Reading about tension will only take you so far. At some point you need to buy a few different sets and try them on your guitar, with your hands, playing your music. Keep notes—it's easy to forget what you tried three months ago. And give each set at least a week or two to settle in before judging; new strings need time to stretch and stabilize.
The good news is that strings are relatively inexpensive compared to other aspects of guitar playing. A few sets of different tensions cost less than a single lesson, and the knowledge you gain will serve you for years. Think of it as an investment in understanding your instrument.
Find Your Perfect Strings
We carry a carefully curated selection of classical guitar strings from Knobloch, D'Addario, Savarez, Hannabach, and more—with detailed tension specifications to help you choose.
Shop Classical Guitar StringsFinal Thoughts
String tension isn't something you set once and forget. As your technique develops, your preferences may change. As you acquire different guitars, you'll discover that each one has its own sweet spot. Even seasonal humidity changes can affect how a particular tension feels on a given instrument.
The goal isn't to find the "best" tension—it's to find what works best for you right now, on your guitar, for the music you're playing. Stay curious, keep experimenting, and trust your hands. They'll tell you when you've found the right match.