Science · free · no sign-up
Frequency Calculator
Waves obey the relationship speed = frequency × wavelength. Enter two values to find the third, for sound, light or radio waves.
Frequency Calculator
f = v / λ — find frequency, wavelength, or wave speed
f = v / λ | T = 1 / f | c = 299,792,458 m/s
Frequency
—
Period (T = 1/f)
—
Angular freq (ω)
—
Wavelength (λ)
—
Wave Speed (v)
—
Step-by-Step
—
About the Frequency Calculator
Waves obey the relationship speed = frequency × wavelength. Enter two values to find the third, for sound, light or radio waves.
How to use the Frequency Calculator
- Enter two of Wave Speed (v), Wavelength (λ) and Frequency (f), and choose the units.
- Press the matching Find button or Calculate.
Formula and method
v = f × λ, so f = v ÷ λ and λ = v ÷ f. The speed of light is 299,792,458 m/s.
Worked example
Light at 600 THz has a wavelength of 299,792,458 ÷ 600 × 10¹² ≈ 500 nm, which is green light.
Tips
- Convert everything to metres and hertz before calculating by hand.
- Sound travels at about 343 m/s in air at 20 °C.
Frequently asked questions
What is the unit of frequency?
The hertz (Hz), meaning one cycle per second.