What is angular frequency?

Angular frequency (omega, measured in rad/s) is the rate of change of angle with time in radians per second. It is related to regular frequency by omega = 2*pi*f. Angular frequency is widely used in physics, electronics, and signal processing. A 1 Hz signal has an angular frequency of 2*pi (approximately 6.28) rad/s.

What are common frequency values to know?

Common frequencies: Human hearing range: 20 Hz to 20 kHz. Concert A: 440 Hz. Power grid (US): 60 Hz. Power grid (Europe): 50 Hz. AM radio: 540 kHz to 1.6 MHz. FM radio: 87.5 MHz to 108 MHz. WiFi 2.4 GHz band: 2.4-2.5 GHz. WiFi 5 GHz band: 5.1-5.8 GHz. Modern CPU: 3-5 GHz. Visible light: 430-750 THz. Microwave oven: 2.45 GHz.

Frequency Converter — Hz, kHz, MHz, GHz, RPM, rad/s & More | LazyTools

📶 Frequency Converter

Frequency Converter — Hz, kHz, MHz, GHz, RPM & More

Q: How do I convert Hz to kHz?

To convert Hz to kHz, divide by 1,000. Example: 1,000 Hz = 1 kHz. 440 Hz (concert A) = 0.44 kHz. 20,000 Hz (upper limit of human hearing) = 20 kHz. To convert back: multiply kHz by 1,000 to get Hz.

Q: How do I convert Hz to MHz?

To convert Hz to MHz, divide by 1,000,000. Example: 1,000,000 Hz = 1 MHz. 100 MHz (FM radio) = 100 MHz. A 3 GHz CPU = 3,000 MHz = 3,000,000,000 Hz. To convert MHz to Hz, multiply by 1,000,000.

Q: How do I convert RPM to Hz?

To convert RPM (revolutions per minute) to Hz, divide by 60. Example: 60 RPM = 1 Hz. 3,600 RPM = 60 Hz. 1,800 RPM = 30 Hz. To convert Hz to RPM, multiply by 60. This relationship is used in motors, engines, and rotating machinery.

Q: How do I convert rad/s to Hz?

To convert radians per second (rad/s) to Hz, divide by 2*pi (approximately 6.2832). Example: 2*pi rad/s = 1 Hz. 100 rad/s = 100/(2*pi) = 15.92 Hz. This is because one full revolution = 2*pi radians = one cycle per second = 1 Hz. To convert Hz to rad/s, multiply by 2*pi.

Q: What is the relationship between frequency and period?

Frequency (f) and period (T) are reciprocals: f = 1/T and T = 1/f. If a signal has a frequency of 1 Hz, its period is 1 second. A 1 kHz signal has a period of 1 millisecond (1/1000 = 0.001 s = 1 ms). A 1 MHz signal has a period of 1 microsecond. Higher frequency means shorter period.

Q: How do I convert GHz to Hz?

To convert GHz to Hz, multiply by 1,000,000,000 (10^9). Example: 1 GHz = 1,000,000,000 Hz = 1 billion Hz. 2.4 GHz (WiFi) = 2,400,000,000 Hz. 5 GHz (WiFi) = 5,000,000,000 Hz. 3 GHz (CPU) = 3,000,000,000 Hz. To convert Hz to GHz, divide by 1,000,000,000.

Q: How do I convert BPM to Hz?

To convert BPM (beats per minute) to Hz, divide by 60. Example: 60 BPM = 1 Hz. 120 BPM = 2 Hz. 180 BPM = 3 Hz. This is because BPM and RPM are both cycles per minute, so the conversion to Hz (cycles per second) is the same: divide by 60.

Q: How do I calculate wavelength from frequency?

For radio waves and light: wavelength = speed of light / frequency = 299,792,458 m/s divided by frequency in Hz. Example: 100 MHz FM radio = 299,792,458 / 100,000,000 = 3 metres wavelength. For sound in air (20C): wavelength = 343 m/s / frequency. Example: 440 Hz (concert A) = 343/440 = 0.78 m wavelength.

Convert between 15 frequency units simultaneously — type in any field and all others update instantly. Covers Hz, kHz, MHz, GHz, THz, mHz, RPM, rad/s, deg/s, BPM and period in s/ms/µs. Includes a wavelength calculator for radio waves and sound. Free, no account.

15 units live Period converter Angular frequency Wavelength calculator Quick examples

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📶 Frequency Converter

Type any value — all 15 units update instantly

Enter a frequency in any unit. Click 📋 to copy any individual value.

Standard Frequency

Hertz

Kilohertz

Megahertz

Gigahertz

Terahertz

Millihertz

Microhertz

Rotational & Angular

RPM

Rev/sec

rad/s

deg/s

BPM

Period (T = 1/f)

Seconds

Milliseconds

Microseconds

Frequency context

Current value

—

Enter a frequency to see context

Wavelength calculator

Based on current frequency

Radio / Light (c = 299,792,458 m/s) —

Sound in air at 20°C (343 m/s) —

Quick examples — click to load

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📖 How to Use

How to convert frequency units

Enter any value

Type a number into any of the 15 unit fields. All other units update instantly as you type — no button needed.

Or use quick examples

Click any reference button (Concert A, WiFi, CPU, FM Radio, etc.) to load a common frequency instantly and see all its equivalent values.

Read the context

The Frequency context panel describes what your entered frequency corresponds to — audio range, radio band, visible light, etc.

Check the wavelength

The wavelength calculator shows the electromagnetic wavelength (using speed of light) and sound wavelength in air at 20°C for your entered frequency.

Copy any value

Click the 📋 copy button next to any unit to copy that specific value to your clipboard. Useful for quickly extracting one converted result.

Convert period values

Use the Period section to enter signal period in seconds, milliseconds, or microseconds. The converter automatically calculates f = 1/T and populates all frequency fields.

✔ Key Features

The most complete free online frequency converter

⚡

15 Units Simultaneously

All 15 frequency and angular frequency units update together from any single input. No need to search for the right converter pair.

🔄

Period Conversion

Enter period in seconds, milliseconds, or microseconds. The converter calculates f = 1/T and fills all frequency fields. Essential for oscilloscope and electronics work.

📐

Angular Frequency

Converts rad/s and deg/s using omega = 2*pi*f and theta = 360*f. Required for physics, signal processing, and control systems.

🌊

Wavelength Calculator

Calculates electromagnetic wavelength (c/f) and acoustic wavelength in air at 20°C (343m/s / f) from the entered frequency. With auto-scaling units.

📺

Frequency Context

Describes what your entered frequency represents — infrasound, human hearing, ultrasound, AM/FM radio, microwave, infrared, visible light, X-ray.

📋

Copy Individual Values

Copy button next to each unit lets you copy a specific converted value without selecting all. Quick and clean for copying one result.

⚡

Quick Reference Examples

10 one-click examples: Concert A, US/EU power grids, FM radio, WiFi 2.4/5 GHz, 3 GHz CPU, THz, and 120 BPM. Load any reference instantly.

🔓

Free, No Account

100% free with no signup, no limits, and no premium tier. Convert as many frequency values as you need without creating an account.

📐 Frequency Guide

Frequency Unit Conversion — Hz, kHz, MHz, GHz, RPM, rad/s Complete Guide

Frequency measures how many times an event repeats per unit of time. One hertz (Hz) means one cycle per second. As frequency increases, we use larger prefixes: kilohertz (kHz = 1,000 Hz), megahertz (MHz = 1,000,000 Hz), gigahertz (GHz = 1,000,000,000 Hz), and terahertz (THz = 10^12 Hz). For very slow periodic events, millihertz (mHz) and microhertz (µHz) are used.

Conversion formulas

Hz to kHz

kHz = Hz / 1,000

440 Hz = 0.44 kHz

Hz to MHz

MHz = Hz / 1,000,000

100,000,000 Hz = 100 MHz

Hz to GHz

GHz = Hz / 1,000,000,000

3,000,000,000 Hz = 3 GHz

RPM to Hz

Hz = RPM / 60

3,600 RPM = 60 Hz

rad/s to Hz

Hz = rad/s / (2 x pi)

6.2832 rad/s = 1 Hz

Period to Hz

Hz = 1 / T (seconds)

T = 1ms = 1,000 Hz

BPM to Hz

Hz = BPM / 60

120 BPM = 2 Hz

Wavelength (radio)

lambda = c / f

c = 299,792,458 m/s

Frequency spectrum reference

Range	Frequency	Applications
Infrasound	< 20 Hz	Earthquakes, large machinery, whale song
Human hearing	20 Hz – 20 kHz	Speech, music, audio equipment
Ultrasound	> 20 kHz	Medical imaging, SONAR, dog whistles
AM radio	540 kHz – 1.6 MHz	AM radio broadcast
FM radio	87.5 – 108 MHz	FM radio broadcast
Microwave	300 MHz – 300 GHz	WiFi, mobile, radar, microwave ovens
WiFi 2.4 GHz	2.4 – 2.5 GHz	802.11b/g/n/ax networks
WiFi 5 GHz	5.1 – 5.8 GHz	802.11a/n/ac/ax networks
Modern CPU	3 – 5.5 GHz	Desktop and laptop processors
5G mmWave	24 – 100 GHz	5G ultra-high speed mobile
Infrared	300 GHz – 430 THz	Thermal cameras, remote controls
Visible light	430 – 750 THz	Human vision (red to violet)
UV light	750 THz – 30 PHz	Sterilisation, tanning, fluorescence

RPM to Hz — motors and rotating machinery

RPM (revolutions per minute) is the standard unit for rotational speed in motors, engines, turbines, and hard drives. Converting to Hz is essential for vibration analysis, resonance calculations, and comparing with electrical supply frequencies. The formula is simple: divide RPM by 60. A standard electric motor at 3,600 RPM runs at 60 Hz — matching the US power grid. A 1,800 RPM motor runs at 30 Hz. An HDD at 7,200 RPM spins at 120 Hz.

Angular frequency (rad/s) in physics and engineering

Angular frequency (omega, measured in radians per second) is used extensively in physics, electrical engineering, and signal processing because it simplifies mathematical expressions involving sinusoidal signals. The relationship is omega = 2 * pi * f. A 50 Hz signal (European power grid) has an angular frequency of 2 * pi * 50 = 314.16 rad/s. Many circuit analysis formulas, impedance calculations, and control system transfer functions use omega directly because it eliminates repeated 2*pi factors.

Period and frequency — the inverse relationship

Period (T) and frequency (f) are exact reciprocals: f = 1/T. A signal with a period of 1 second has a frequency of 1 Hz. A period of 1 millisecond (0.001 s) = 1,000 Hz = 1 kHz. A period of 1 microsecond = 1 MHz. Oscilloscopes typically display period, so converting to frequency is a routine task. The Period section in this converter accepts time values in seconds, milliseconds, or microseconds and converts to all frequency units automatically.

❓ FAQ

Frequency converter FAQ

How do I convert Hz to kHz?▾

Divide Hz by 1,000. Example: 1,000 Hz = 1 kHz. 440 Hz = 0.44 kHz. 20,000 Hz = 20 kHz. To convert kHz back to Hz, multiply by 1,000.

How do I convert Hz to MHz?▾

Divide Hz by 1,000,000. Example: 100,000,000 Hz = 100 MHz. 3,000,000,000 Hz = 3,000 MHz = 3 GHz. To convert MHz to Hz, multiply by 1,000,000.

How do I convert RPM to Hz?▾

Divide RPM by 60. 60 RPM = 1 Hz. 3,600 RPM = 60 Hz. 1,800 RPM = 30 Hz. To convert Hz to RPM, multiply by 60. Used for motors, engines, and rotating machinery.

How do I convert rad/s to Hz?▾

Divide rad/s by 2*pi (approximately 6.2832). Example: 2*pi rad/s = 1 Hz. 100 rad/s = 15.92 Hz. To convert Hz to rad/s, multiply by 2*pi. Angular frequency omega = 2*pi*f.

What is the relationship between frequency and period?▾

They are reciprocals: f = 1/T and T = 1/f. A 1 Hz signal has a period of 1 second. A 1 kHz signal has a period of 1 ms. A 1 MHz signal has a period of 1 microsecond. Higher frequency means shorter period.

How do I convert GHz to Hz?▾

Multiply GHz by 1,000,000,000. 1 GHz = 1,000,000,000 Hz. 2.4 GHz (WiFi) = 2,400,000,000 Hz. 3 GHz (CPU) = 3,000,000,000 Hz. To convert Hz to GHz, divide by 1,000,000,000.

How do I convert BPM to Hz?▾

Divide BPM by 60. 60 BPM = 1 Hz. 120 BPM = 2 Hz. 180 BPM = 3 Hz. BPM and RPM use the same formula since both measure cycles per minute. To convert Hz to BPM, multiply by 60.

How do I calculate wavelength from frequency?▾

For radio/light: wavelength = 299,792,458 m/s / frequency (Hz). For sound in air at 20C: wavelength = 343 m/s / frequency (Hz). Example: 440 Hz sound = 343/440 = 0.78 m. The wavelength calculator above does this automatically.

What are common frequency values?▾

Human hearing: 20 Hz to 20 kHz. Concert A: 440 Hz. US power: 60 Hz. EU power: 50 Hz. AM radio: 540 kHz to 1.6 MHz. FM radio: 87.5 to 108 MHz. WiFi 2.4 GHz. WiFi 5 GHz. CPU: 3-5 GHz. Visible light: 430-750 THz. Microwave oven: 2.45 GHz.

Frequency converter free no signup▾

The LazyTools Frequency Converter is 100% free with no signup. Enter any value in any of the 15 units and all others convert instantly. Includes wavelength calculator and quick examples. No account, no limits.

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