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Frequency Calculator (f=1/T)

Quick answer

This calculator converts between frequency, period, wavelength, and angular frequency: f = 1/T, lambda = c/f, omega = 2 pi f.

  • Enter one value and get all others instantly.

Figures are estimates from this calculator’s standard formula — adjust the inputs in the tool below for your exact number.

How the Frequency Calculator Works

f = 1/T, λ = c/f, ω = 2πf

Calculates the relationships between frequency, period, wavelength, and angular frequency. These are fundamental properties of all wave phenomena. Worked example: a 2.4 GHz WiFi channel has period T = 1/2.4e9 = 0.417 ns and wavelength 3e8/2.4e9 = 12.5 cm. Its angular frequency is 2 pi x 2.4e9 = 15.1 Grad/s. Mains and radio pair the same formulas: 50 Hz power has a 20 ms period and 6000 km wavelength, while a 100 MHz FM station repeats every 10 ns with 3 m waves - one calculator covers both worlds.

  1. 1

    Step 1

    Select what you want to calculate

  2. 2

    Step 2

    Enter the known value (frequency, period, or wavelength)

  3. 3

    Step 3

    View all related wave properties

  4. 4

    Step 4

    Use angular frequency for circuit analysis

Use Cases

Converting between frequency and period

Calculating antenna lengths from frequency

Understanding AC circuit timing

Analyzing electromagnetic spectrum properties

Tips

  • 1

    Period (T) = 1/frequency in seconds

  • 2

    Wavelength depends on medium (use c for EM waves)

  • 3

    Angular frequency ω = 2πf radians/second

  • 4

    Higher frequency = shorter wavelength

Common Mistakes

  • Confusing Hz with rad/s (multiply by 2π)

  • Using speed of light for sound waves

  • Not converting units (MHz, kHz, GHz)

  • Forgetting velocity factor for transmission lines

FAQs

What is the difference between frequency and angular frequency?

Frequency (f) is cycles per second in Hz. Angular frequency (ω) is radians per second = 2πf. Angular frequency is used in AC circuit analysis and phasor calculations.

How does wavelength change in different media?

Wavelength = velocity/frequency. In materials, wave velocity is slower than in vacuum, so wavelength is shorter. This is why fiber optic cables have velocity factor < 1.

What frequency range is audible?

Humans hear approximately 20 Hz to 20 kHz. Below 20 Hz is infrasound, above 20 kHz is ultrasound. Radio frequencies start around 3 kHz and extend to 300 GHz.

How do I convert period to frequency?

f = 1/T. A period of 20 ms means f = 1/0.02 = 50 Hz (European mains). A 10 ns pulse repetition gives 100 MHz. Frequency and period are exact reciprocals.

What is the wavelength formula?

lambda = v/f, where v is wave speed. Radio in air: lambda = 300/f(MHz) meters, so 100 MHz gives 3 m and 2.4 GHz gives 12.5 cm. In coax cable multiply by the velocity factor, typically 0.66.

What is angular frequency?

omega = 2 x pi x f, in radians per second. A 50 Hz supply has omega = 314 rad/s. Reactance formulas use omega: XL = omega L and XC = 1/(omega C), which is why engineers keep both forms handy.