Frequency Converter

1Hertz = 0.001Kilohertz

0.001

International System (SI)

Hertz (Hz)1

Kilohertz (kHz)0.001

Megahertz (MHz)0.000001

Gigahertz (GHz)1.00×10⁻⁹

Free online frequency unit conversion tool supporting instant bidirectional conversion between 4 commonly used SI frequency units: hertz (Hz), kilohertz (kHz), megahertz (MHz), gigahertz (GHz). Enter a value in any unit and results for other units update synchronously in real time — no button clicks required. Covers all commonly used frequency ranges from power line frequency 50/60Hz, audio 20Hz~20kHz, ultrasonic/switching power supplies at kHz level, FM broadcast/CPU clocks at MHz level, to WiFi/5G communications at GHz level. All conversions run locally in your browser; data is never uploaded to servers, protecting the privacy of your engineering parameters.

Unit Converter

One-stop entry for 35+ unit conversions

Time conversion

Frequency period T=1/f; time units seconds/milliseconds/microseconds/nanoseconds are reciprocals of Hz/kHz/MHz/GHz

Use Cases

Electronic engineers quickly convert Hz/kHz/MHz/GHz during circuit design for clock circuits and RF front-end design
Radio/Ham enthusiasts convert kHz/MHz frequencies to wavelength when operating HF/VHF/UHF, calculating dipole antenna dimensions
Audio engineers quickly convert Hz/kHz when working with sample rates, filter cutoff frequencies, and EQ bands
WiFi/Bluetooth/4G/5G network optimization engineers convert GHz frequencies to wavelength, path loss, and Doppler shift references
Students doing frequency-period-wavelength conversion homework in physics class when studying waves, sound, and electromagnetism
Music producers/sound engineers adjusting Hz/kHz bands on equalizers (EQ) (low frequency 80Hz, midrange 1kHz, high frequency 10kHz)
Switching power supply design: 65kHz/100kHz/200kHz/400kHz switching frequencies correspond to EMI filter selection
MCU/embedded development configuring system clocks, multiplying external 8MHz crystals via PLL to system 72/168/400MHz
RFID/NFC developers working with 13.56MHz, 868/915MHz carrier frequencies and antenna matching circuits
Quickly converting frequency points between Hz/kHz/MHz/GHz scales when using spectrum analyzers/oscilloscopes
Converting FM/AM radio reception frequencies 88~108MHz (FM), 530~1710kHz (AM) to tuning digits
Walkie-talkies/amateur radio calculating wavelength and selecting antennas in VHF(144MHz)/UHF(430MHz) bands
Microwave oven operating frequency 2450MHz=2.45GHz; note interference since WiFi 2.4GHz is in the same band
Calculating period (ns) from GHz-level signal frequencies for PCB high-speed circuit design, doing matched-length trace routing (1ns≈15cm on FR4 boards)
Power/electricians converting units when working with 50/60Hz mains frequency and inverter output frequencies
Frequency selection for ultrasonic ranging (40kHz), ultrasonic cleaning (28/40kHz), medical ultrasound (2~18MHz)
High-speed serial buses: USB 3.0 5Gbps, PCIe Gen3 8GT/s, SATA 6Gbps correspond to GHz-level clocks
Converting satellite navigation frequencies: GPS L1 band 1575.42MHz, BeiDou B1 1561MHz, GLONASS, etc.

How to Use

Select source unit
Enter frequency value
Select target unit
Read result and copy

Features

Full coverage of 4 SI frequency units: hertz (Hz), kilohertz (kHz), megahertz (MHz), gigahertz (GHz), covering all commonly used magnitudes from power frequency, audio to RF and microwave
Instant bidirectional conversion: entering a value in any input field triggers real-time linked calculation for other units — no convert button needed, zero learning curve
Based on international standard conversion factors: 1 kHz = 1000 Hz, 1 MHz = 1000 kHz = 1,000,000 Hz, 1 GHz = 1000 MHz = 10⁹ Hz, strictly following SI decimal prefixes
Automatic scientific notation display: spanning 9 orders of magnitude between Hz and GHz, extremely small/large values automatically render in scientific notation to avoid zero clutter
Browser-local computation: all conversion logic executes in frontend JavaScript; values never leave your device — zero network requests, zero server-side logs
Responsive design compatible with phones/tablets/desktops; radio enthusiasts, audio engineers, and students can quickly convert during experiments
Supports decimal and scientific notation input; cross-magnitude conversions (e.g., 2.4GHz to Hz) produce accurate results
Quickly associate physical quantities like wavelength and period mentally, aiding RF debugging, antenna design, and signal analysis

Best Practices

FAQ

What is the basic unit of frequency? What are the conversion relationships?

The SI base unit of frequency is the hertz, symbol Hz, named after German physicist Heinrich Hertz. 1Hz means 1 vibration per second (1Hz=1/s). Common decimal-multiple units: 1 kHz (kilohertz) = 1000 Hz = 10³ Hz; 1 MHz (megahertz) = 1000 kHz = 10⁶ Hz; 1 GHz (gigahertz) = 1000 MHz = 10⁹ Hz. Each level is a factor of 1000. For example, 2.4GHz = 2,400,000,000 Hz; medium-wave AM broadcast at 1000kHz = 1MHz.

What is the relationship between frequency f and period T?

Frequency and period are reciprocals of each other: T = 1/f, f = 1/T. Frequency represents vibrations per second; period represents the time for one vibration. For example, 50Hz mains power corresponds to period T=1/50=0.02 seconds=20 milliseconds; a 1kHz signal has period 1ms; a 1MHz signal has period 1μs; a 1GHz signal has period 1ns. Higher frequency means shorter period; GHz-level signals have periods of just 1 nanosecond, making them very sensitive to PCB trace length (1ns≈30cm light-speed propagation distance).

How do you convert between frequency and wavelength?

The relationship between electromagnetic wave wavelength λ and frequency f is: λ = c/f, where c≈3×10⁸m/s (speed of light). For example, FM broadcast at 100MHz corresponds to wavelength λ=3×10⁸/10⁸=3 meters; WiFi 2.4GHz corresponds to wavelength 12.5cm; WiFi 5GHz corresponds to wavelength 6cm; 4G LTE 1.8GHz corresponds to 16.7cm. Wavelength determines antenna size (common dipole antenna length=λ/2 or λ/4); higher frequency means shorter wavelength and smaller antennas.

What scenarios use Hz-level frequencies (1~999Hz)?

Hz is the most fundamental frequency unit. Typical applications: mains power frequency 50Hz (China/Europe), 60Hz (USA/Japan); low-frequency segment of human audible range 20Hz~20kHz; music standard pitch A4=440Hz; normal heartbeat 60~100 bpm≈1~1.7Hz; seismic waves below a few Hz; brainwave alpha waves 8~13Hz; low-end CPU clocks like 32.768kHz real-time clock crystals (RTC) are at kHz level; mechanical vibration, motor rotational frequency, etc.

What scenarios use kHz-level frequencies (1~999kHz)?

kHz covers: full audio band 20Hz~20kHz; ultrasonic cleaning/ranging 20kHz~200kHz; medium-wave AM broadcast 530~1710kHz; switching power supply operating frequencies from tens to hundreds of kHz (common 65kHz/100kHz/200kHz/400kHz); DC-DC converters, flyback/forward converters; I²S audio sample rates 44.1kHz/48kHz/96kHz/192kHz; RTC crystal 32.768kHz; intermediate frequency amplifiers; PLC power line carrier 10~500kHz; bioelectric signal acquisition.

What scenarios use MHz-level frequencies (1~999MHz)?

MHz covers extremely wide applications: FM broadcast 88~108MHz; shortwave/ultra-shortwave communications 3~30MHz (HF), 30~300MHz (VHF); aviation communications 118~136MHz; walkie-talkie VHF/UHF bands; RFID 13.56MHz (NFC), 868/915MHz; FM radios, TV broadcast; MCU/CPU clocks from tens to hundreds of MHz (STM32 commonly 72/168/400MHz); USB 480Mbps high-speed signals; Bluetooth 2.4GHz (crosses into GHz); FM/FSK wireless modules 315/433MHz.

What scenarios use GHz-level frequencies (1GHz and above)?

GHz covers modern high-speed communications and computing: WiFi 2.4GHz/5GHz/6GHz (Wi-Fi 6E); Bluetooth 2.4GHz; microwave ovens 2.45GHz; 4G LTE 700MHz~2.6GHz (partially enters GHz); 5G Sub-6GHz bands and millimeter wave 24~40GHz; satellite communications C/Ku/Ka bands (4~40GHz); modern PC/mobile CPUs 2~4GHz multi-core; DDR memory clocks 1.6~6.4GHz; USB 3.x 5/10Gbps; PCIe/SerDes; radar, microwave ranging; UWB ultra-wideband 3~10GHz.

What is the human audible frequency range? Why are 44.1kHz/48kHz commonly used for audio sample rates?

Human audible range is approximately 20Hz~20kHz (high-frequency hearing declines with age; adults typically only hear up to 15~17kHz). According to the Nyquist sampling theorem, the sample rate must be greater than twice the highest signal frequency to reconstruct without distortion. CD-quality sample rate 44.1kHz covers 20kHz audio (2×20k=40k<44.1k) with a small transition band margin; professional audio/video commonly uses 48kHz (synchronized with video frame rates); Hi-Res high-resolution audio uses 88.2/96/192kHz to preserve more airiness and overtones.

What are common crystal oscillator frequencies?

Common quartz crystal frequencies: 32.768kHz (RTC real-time clock, 2^15 convenient for dividing down to 1 second); 8MHz, 12MHz, 16MHz (classic MCU/USB/AVR clocks); 11.0592MHz (for precise serial baud rate division); 25MHz (Ethernet MII); 24MHz (USB full-speed); 27MHz (USB high-speed, video); 14.31818MHz (derived from NTSC color subcarrier, old PC system clock); 48MHz (USB); 50MHz (FPGA/PCIe reference clock).

What is the typical division of Hz/kHz/MHz/GHz in wireless communication bands?

International Telecommunication Union (ITU) band designations: ELF extremely low frequency <3kHz (power/submarine communications); VLF very low frequency 3~30kHz (longwave navigation); LF low frequency 30~300kHz (longwave broadcast/AM Europe); MF medium frequency 300~3000kHz (medium-wave AM broadcast 530~1710kHz); HF high frequency 3~30MHz (shortwave communications, radio SW band); VHF very high frequency 30~300MHz (FM broadcast 88~108MHz, TV, walkie-talkies); UHF ultra high frequency 300~3000MHz (4G, WiFi 2.4G, Bluetooth, walkie-talkies); SHF super high frequency 3~30GHz (WiFi 5G, 5G Sub-6, microwave, satellite); EHF extremely high frequency 30~300GHz (millimeter wave 5G, radar).

Is higher CPU clock speed in GHz always faster? What is the relationship between clock speed, period, and instruction execution?

CPU clock speed represents clock cycles per second; 1GHz = 1 billion clock cycles per second. Each clock cycle T=1/f is the CPU's most basic time unit; for example, a 3GHz CPU has a cycle of about 0.33ns. Generally, for CPUs of the same architecture, higher clock speed means faster execution, but different architectures cannot be simply compared by GHz (e.g., ARM and x86 have different instructions per cycle, IPC). Overclocking means raising the clock speed to a higher GHz value, but increases heat and power consumption. In recent years, multi-core + improving IPC have become more common than simply cranking up GHz.

Which frequency units does this tool support? Why no THz, rpm, BPM?

This tool supports 4 SI frequency units: Hz (hertz), kHz (kilohertz), MHz (megahertz), GHz (gigahertz), covering over 99% of daily use scenarios in electronic engineering, radio, audio, and communications. THz (terahertz=10¹²Hz) is mainly used in extremely specialized research fields like terahertz spectroscopy and security imaging; rpm (revolutions per minute) is a mechanical rotational speed unit, 1rpm≈0.0167Hz, belonging to the mechanical domain; BPM (beats per minute) is a music tempo unit, normal 60~180BPM≈1~3Hz. We will evaluate adding higher-frequency units if needed in the future.

Glossary

Hertz (Hz): SI base unit of frequency, 1Hz=1 repetition/second=1s⁻¹, named after German physicist Heinrich Hertz, who first experimentally confirmed the existence of electromagnetic waves in 1887.
kHz (kilohertz): 1kHz=1000Hz=10³Hz, covering audio bands, switching power supplies, ultrasound, AM medium-wave broadcast, RTC real-time clock crystals, etc.
MHz (megahertz): 1MHz=1000kHz=10⁶Hz, covering FM broadcast, VHF/UHF walkie-talkies, MCU clocks, RFID/NFC, entry-level CPU clocks, etc.
GHz (gigahertz): 1GHz=1000MHz=10⁹Hz, covering WiFi/Bluetooth, 4G/5G communications, modern CPU/GPU/SoC clock speeds, radar/microwave, high-speed serial buses, etc.
Period: Time required for one complete vibration, symbol T, unit seconds (s), T=1/f. Higher frequency means shorter period; 50Hz mains period is 20ms, 1GHz period is 1ns.
Wavelength: Distance a wave travels in one period, symbol λ, λ=c/f (for electromagnetic waves c=speed of light≈3×10⁸m/s). Determines antenna size (commonly λ/2 or λ/4).
Nyquist Theorem: Sampling theorem: sampling frequency must be greater than twice the highest signal frequency (fₛ≥2fₘₐₓ) to reconstruct the original signal without distortion from sampled data, determining that digital audio must be ≥40kHz.
Angular Frequency: ω=2πf, unit rad/s, used for sinusoidal AC, inductive/capacitive reactance calculations in AC circuits. Differs from this tool's frequency f by a factor of 2π.

Privacy & Security

All frequency unit conversions on this page run entirely in your browser. The frequency values you enter never leave your device — no network requests, no server logs. Input is cleared when you close the page. Engineers' design parameters and RF debugging data are private; we do not collect any data.