Wavelength & Frequency Calculator
Convert between wavelength and frequency with c = λf. Solve for wavelength, frequency, or wave speed, defaulting to the speed of light c = 299,792,458 m/s.
Wavelength (λ = v / f)
2.99792 m
Wave equation: v = λ × f. For light in a vacuum, v = c = 299,792,458 m/s. Frequency is in hertz (Hz); enter scientific notation like 1e8 for large values.
Frequently Asked Questions
What is the relationship between wavelength and frequency?
Wave speed equals wavelength times frequency: v = λ × f. For electromagnetic waves in a vacuum, v is the speed of light c = 299,792,458 m/s, so c = λf.
How do I convert frequency to wavelength?
Divide the wave speed by the frequency: λ = v / f. For light, λ = c / f. For example, a 100 MHz radio wave has wavelength 299,792,458 / 100,000,000 ≈ 3 m.
How do I convert wavelength to frequency?
Divide the wave speed by the wavelength: f = v / λ. For light, f = c / λ. A 500 nm green light wave has frequency ≈ 6.0 × 10¹⁴ Hz.
What is the speed of light?
The speed of light in a vacuum is exactly 299,792,458 metres per second. It is the default wave speed in this calculator for electromagnetic waves.
Can I use this for sound waves?
Yes. Change the wave speed to the speed of sound (about 343 m/s in air at 20 °C) and the same v = λf relationship applies.