Thunder arrives late because sound is slow — about a mile every five seconds. Every sound wave obeys one relation: wave speed equals frequency times wavelength, v = f × λ. High-pitched sounds pack more waves per second into the same speed, so their wavelengths shrink; a 20 Hz bass note stretches about 56 feet long in air, while a 20 kHz squeal at the edge of hearing squeezes into two-thirds of an inch.

This calculator runs that multiplication. Type the frequency in hertz into Variable A and the wavelength in your chosen length unit into Variable B; the Result box gives the wave speed in that unit per second. A sound engineer in Nashville checking a 440 Hz tuning note with its 2.55-foot wavelength, for instance, reads about 1,122 ft/s — confirming the textbook 1,125 ft/s speed of sound in room-temperature air. Flip it around for lightning: count the seconds between flash and thunder, multiply by roughly 1,100 ft/s here, and you have the storm's distance in feet. Concert-hall designers use the same equation to place reflections within the ear's 50-millisecond fusion window.

With the pre-filled defaults — Variable A 10, Variable B 5 — the Sound Calculator returns Result 50.0000. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.