Frequency to Wavelength Calculator

In short Wavelength is the speed of sound divided by the frequency, and in air at 20 °C sound travels about 343 metres per second — so a 100 Hz note is 3.43 metres long and a 40 Hz note is over 8.5 metres. That length is why bass behaves so differently from treble in a room. A wave whose half-wavelength matches a room dimension resonates, and since half of 8.5 metres is longer than most rooms are wide, low frequencies are dominated by the room rather than by the loudspeaker. It is also why bass traps have to be so much thicker than the foam used for treble: a porous absorber needs roughly a quarter of a wavelength of depth to work at a given frequency, which is over two metres at 40 Hz and about 4 cm at 2 kHz. Temperature matters more than people expect. The speed of sound rises by roughly 0.6 metres per second for every degree, so a cold hall and a warm one differ by several metres per second — enough to shift the pitch of a wind instrument noticeably, since the air inside it is what is resonating. Humidity and altitude have far smaller effects. What does NOT change is the dependence on frequency: unlike light in glass, sound of every pitch travels at the same speed through air, which is why a distant marching band stays in time with itself instead of arriving as a smear.