Frequency Calculator - Period, Frequency & Wave Speed
Convert between period and frequency (f = 1/T), plus a wave speed mode relating frequency, wavelength, and propagation speed.
Period ↔ Frequency
Frequency calculated from period.
Wave Speed (f × λ = v)
343.0000
v = f × λ = 50 × 6.86 = 343.0000
How to Calculate Frequency from Period
Frequency is the number of complete cycles that occur per second, and period is the time it takes to complete a single cycle. The two are reciprocals of each other — enter either value below and the other updates instantly. A secondary Wave Speed mode also lets you relate frequency, wavelength, and wave speed for any wave (sound, electromagnetic, or otherwise), solving for whichever one you're missing.
Example
A signal that completes one cycle every 0.02 seconds has a frequency of f = 1 / 0.02 = 50 Hz — the standard AC mains frequency in much of the world. For a wave traveling at 343 m/s (the speed of sound in air) with a frequency of 50 Hz, the wavelength is λ = 343 / 50 = 6.86 meters.
Common Use Cases
- Converting between a signal's period and its frequency in electronics or physics.
- Working out AC mains frequency, clock speeds, or oscillation rates.
- Relating frequency, wavelength, and propagation speed for any generic wave.
FAQs
What's the difference between period and frequency?
Period is the time taken for one complete cycle, measured in seconds. Frequency is how many cycles happen per second, measured in Hertz (Hz). They are exact reciprocals: f = 1/T and T = 1/f.
How is this different from a wavelength calculator?
A dedicated wavelength calculator usually fixes the wave speed to a known constant, like the speed of light or the speed of sound. The Wave Speed mode here is fully generic — enter any propagation speed — so it works for water waves, seismic waves, or any custom scenario, not just light or sound.
Can frequency or period be negative or zero?
No — both must be positive numbers greater than zero, since a cycle can't take zero or negative time, and a frequency of zero would mean no oscillation at all.