Compare guitar tonewoods by stiffness-to-weight ratio and resonant frequency. Supports sitka spruce, cedar, mahogany, maple, rosewood, ebony, walnut and alder.
Select a species and the tool reports its nominal density, its stiffness-to-weight ratio (elastic modulus divided by density), and an approximate longitudinal resonant frequency for a default 490 mm plate. A high stiffness-to-weight ratio means the plate can move air efficiently without carrying excess mass, which is exactly what makes a top responsive.
Sitka spruce leads the soundboard woods with a ratio near 25.6 (0.43 g/cm³, 11.0 GPa) and a 490 mm resonant frequency around 5,161 Hz. Western red cedar is close behind and lighter still. Among the denser woods, rosewood (0.85 g/cm³, 11.7 GPa) lands near 13.8 and ebony near 15.5 — these belong on backs, sides and fingerboards rather than tops.
Mahogany (0.55 g/cm³, 9.7 GPa) sits around 17.6 with a resonant frequency near 4,285 Hz, giving the warm, sustain-focused midrange it is prized for, while maple offers a bright, tight, focused voice. The resonance figure uses f = √(E/ρ) ÷ (2L) for a longitudinal bar mode (after Bader, 2005); treat it as a relative comparison between species, not the tuned tap-tone of a finished, braced plate.
A high stiffness-to-weight ratio means a plate can resist bending while staying light, so it converts string energy into sound efficiently rather than soaking it up as mass. That is what gives a responsive, dynamic top with good headroom. The tool computes the ratio as elastic modulus divided by density.
Among the woods modeled here, sitka spruce leads with a ratio near 25.6 (0.43 g/cm³, 11.0 GPa), which is exactly why it dominates steel-string and many classical soundboards. Western red cedar is close behind and a little warmer and lighter, favored for fingerstyle.
It is the longitudinal bar resonance of a 490 mm plate, f = √(E/ρ) ÷ (2L), after Bader (2005). Sitka spruce lands near 5,161 Hz and mahogany near 4,285 Hz. Read it as a relative comparison between species, not the tuned tap tone of a finished, braced and shaped plate, which depends heavily on thickness and bracing.
Dense, lower-ratio woods belong on backs, sides and fingerboards rather than tops. Rosewood (0.85 g/cm³, ratio ≈ 13.8) adds rich bass and complex overtones as a back-and-sides wood, while ebony (1.10 g/cm³, ratio ≈ 15.5) is bright, articulate and hard-wearing — perfect for fingerboards and bridges where stiffness and durability matter more than light weight.