September 25, 2025 •Brendan Murphy
Choosing a piano is about more than just aesthetics or budget. One of the most overlooked—but most important—factors is size. Whether you’re considering an upright, a baby grand, or a full concert grand, the dimensions of your piano directly affect its tone quality, volume output, and overall resonance.
Why Size Matters in Piano Sound
At its core, a piano is an acoustic instrument where sound is created by felt hammers striking strings. The strings vibrate and transfer energy to the soundboard. The larger the piano, the longer the strings and the greater the soundboard area—which results in more powerful, richer, and more resonant sound.
Small vs Large Pianos: The Physics
- Small Upright or Baby Grand: Shorter strings, smaller soundboard = limited bass response, thinner tone.
- Medium Grand (5'7"–6'2"): Balanced tone, stronger bass, good volume for most homes.
- Concert Grand (8'+): Full spectrum clarity, deep bass, and projection ideal for large venues.
Key Size and Control
Beyond string length and soundboard area, the physical size of the piano also influences the length of the keys themselves—specifically, the full key stick that extends back into the piano, not just the visible part. Larger pianos (7’+) typically feature longer key sticks. This increased length provides several advantages for the player:
Enhanced Control: A longer key stick acts as a longer lever, offering the pianist greater mechanical advantage and a more nuanced feel. This allows for finer control over the hammer's impact on the strings.
Improved Dynamic Range: The superior control afforded by longer keys directly translates to a wider dynamic range. It becomes easier to achieve very soft passages (pianissimo) with precision, as well as powerful fortes, due to the increased leverage and responsiveness.
Easier Soft Playing: The added control makes it significantly easier to play softly and evenly, as the slight variations in touch translate more effectively through the longer key mechanism.
Upright vs. Grand: What’s the Real Difference?
While many assume upright and grand pianos differ only in form, the sound differences are significant. Upright pianos compress the action vertically, limiting the length of the strings and soundboard. Upright actions rely on springs to reset the hammer. Grand pianos offer horizontal string alignment, allowing better gravity-assisted action, richer tone, and increased dynamic range.
Tone, Volume, and Resonance Explained
Tone: Influenced by string length, key length, hammer action, and voicing. Larger pianos offer more nuance.
Volume: Depends on how much energy the soundboard can project. Bigger instruments = more sound.
Resonance: Longer strings vibrate more deeply and sustain tones longer, creating lush harmonics.
Does Size Equal Quality?
Not always. A well-crafted upright like the Steinway Model K can outperform a poorly built grand. But within the same quality tier, size improves performance.
What About Value?
Larger pianos, especially from premium brands like Steinway & Sons, often tend to hold value due to their musical capabilities and desirability among advanced players and institutions.
Matching Piano Size to Your Space & Goals
- Small Space or Apartment? Upright or baby grand with quiet-play technology.
- Teaching Studio or Music Room? Steinway Model B or Model O, Boston GP-178 or Essex EGP-173 for balance.
- Professional Performance or Recording? Steinway Model B or Model D.
Final Notes
Piano size shapes your sound experience. If you're exploring options, visit our showroom or connect with a piano consultant to compare in person.
Curious how different piano sizes sound in your space? Book an appointment or download our free Piano Buyer’s Guide.