Free Engineering Tool

Frequency to Wavelength Calculator

Calculate wavelength from frequency for different propagation media — air, water, steel, or vacuum (electromagnetic waves). Shows wavelength in multiple units, wave period, and wave number.

λ = v / f Sound & EM Waves Multi-Medium

Results

Wavelength

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Wavelength (mm)

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Wavelength (μm)

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Wavelength (nm)

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Wave Period T

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Wave Number k

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Angular Frequency ω

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Propagation Speed

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Fundamental Wave Equation

The relationship between wavelength, frequency, and propagation speed is:

Where λ (lambda) is wavelength in meters, v is wave speed in m/s, and f is frequency in Hz.

Related Quantities

T = 1/f (wave period, seconds)

k = 2π/λ (wave number, rad/m)

ω = 2πf (angular frequency, rad/s)

Speed of Sound in Various Media

Medium	Speed (m/s)	Temperature
Air	343.2	20 °C
Fresh water	1497	25 °C
Seawater	1531	25 °C
Steel	5960	20 °C (longitudinal)
Aluminum	6420	20 °C (longitudinal)
Concrete	~3400	varies
Vacuum (EM waves)	299,792,458	exact (c)

For vibration analysis: knowing the wavelength helps determine optimal sensor placement spacing and understand mode shapes. The wavelength in steel at machine vibration frequencies (10–1000 Hz) is typically 6–596 meters — much longer than the machine itself.

Electromagnetic Spectrum Reference

Type	Frequency Range	Wavelength Range
Radio waves	3 kHz – 300 GHz	1 mm – 100 km
Microwaves	300 MHz – 300 GHz	1 mm – 1 m
Infrared	300 GHz – 400 THz	700 nm – 1 mm
Visible light	400–790 THz	380–700 nm
Ultraviolet	790 THz – 30 PHz	10–380 nm
X-rays	30 PHz – 30 EHz	0.01–10 nm