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Frequency Converter

Created by Joanna Śmietańska, PhD
Reviewed by Steven Wooding
Last updated: Jan 18, 2024

Our frequency converter will instantly convert one frequency value into another unit of frequency.

Frequency informs us how often something is repeated and is a parameter commonly used in electricity, waves, or rotational motion.

Keep reading, and we'll tell you more about what frequency is, what is the unit of frequency, and the frequency symbol.

What is frequency?

At its most basic, frequency describes physical actions that cyclically repeat many times, such as oscillations and rotational motion. Frequency determines the number of cycles per unit time.

Frequency is measured in many applications, which include:

  • Electrical circuits — Frequency is the number of repetitions of the sine wave during a positive-to-negative cycle.

  • Waves — The frequency gives us the number of waves that pass through a point at a selected time. Check here how to find sound frequency.

  • Light waves — The visible spectrum color depends on the frequency of the wave, e.g., 400 THz (4 × 1014 Hz) is red light, and 800 THz (8 × 1014 Hz) is violet light.

  • A healthy person's heart beats at a frequency of 45 to 220 beats per minute.

What is the unit of frequency?

The symbol for frequency is the letter f, and the SI unit of frequency is hertz (Hz), where 1 hertz equals one cycle per second. Hence, it follows that the more cycles per second, the higher the frequency.

In rotational motion, we use traditional units referred to as rotational frequency, such as revolutions per minute (rpm) and degrees per second (deg/s). One hertz is equal to 60 rpm: 1 Hz = 60 rpm.

Angular frequency (denoted as the Greek letter omega, ω) describes the angular displacement of a body per unit of time. Since a body moves along a circular path and its displacement involves an angle, the unit of angular frequency is usually radians per second (rad/s). Learn more from this angular frequency calculator.

Other SI units of frequency

Omni's frequency converter uses the following units of frequency converted into hertz, including the angular frequency units:

Frequency unit

Value in hertz [Hz]

picohertz (pHz)

1 x 10⁻¹²

nanohertz (nHz)

1 x 10⁻⁹

microhertz (μHz)


millihertz (mHz)


centihertz (cHz)


decihertz (dHz)


decahertz (daHz)


hectohertz (hHz)


kilohertz (KHz)


megahertz (MHz)


gigahertz (GHz)

1 x 10⁹

terahertz (THz)

1 x 10¹²

revolutions per minute (RPM)


revolutions per hour (RPH)

2.7 x 10⁻⁴

radians per second (rad/s)


degrees per second (deg/s)

2.7 x 10⁻³

Examples of how to calculate frequency

There are three basic formulas for how to calculate the frequency, and they are discussed in detail in our frequency calculator. The frequency is related to the period T, i.e., the time required for one cycle of oscillation or rotation, by the following relation:

f=1T\small{f = \frac{1}{T}}

The frequency formula in terms of wavelength λ and wave speed ν is as follows (read more about this relationship in our frequency to wavelength calculator):

f=νλ\small{f = \frac{\nu}{\lambda}}

Finally, frequency and angular frequency ω are related in this way:

f=ω2π\small{f = \frac{\omega}{2 \pi}}

How to use this frequency converter

Using our frequency converter is pretty simple and intuitive. Just follow these steps:

  1. Type frequency value which you want to convert. The default unit is hertz, but you can freely modify the frequency units. For example, convert MHz to Hz by entering 5 MHz in the field. The result is 5 x 10⁶ Hz.

  2. Now let us convert from Hz to rad/s. Type 60 Hz (utility frequency of AC in your home) and convert from Hz to rad/s. You will get 376.99 radians per second. 🙌


What does Hz mean?

The Hz (hertz) is the SI unit of frequency. It can be expressed as s⁻¹, meaning something happens once in a second. The unit is named after Heinrich Rudolf Hertz, the first person to provide conclusive proof of the existence of electromagnetic waves.

How can I find the frequency of a wave?

Use frequency formulas to calculate the wave frequency:

  1. Divide wave speed by the wavelength. For instance, if a wave is traveling 5 m/s and it has a 4-meter wavelength, the frequency will be 5 m/s / 4 m = 1.25 Hz.

  2. Divide 1 by the time it takes for the wave to complete a full cycle (period). If the wave needs 0.2 seconds to complete one full cycle, then the wave frequency is 5 Hz.

What is the frequency of light?

The visible light frequency is approximately 400 THz (red light) to 700 THz (violet light). A THz (terahertz) is a unit of frequency equal to 1 x 10¹² Hz. The frequency of a light wave determines the color we see. Lower frequencies (longer wavelengths) correspond to "warmer" colors, while higher frequencies (and shorter wavelengths) correspond to "cold" colors.

How many Hz is 100 MHz?

100,000,000 Hz or 1 x 10⁸ Hz. To convert MHz to Hz:

  1. Find the conversion factor for MHz: 1,000,000.
  2. Multiply 100 MHz by 1,000,000.
  3. Get the result in Hz: 100,000,000.
Joanna Śmietańska, PhD
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