Frequency Converter Online — Convert Hz, kHz, MHz, GHz, rad/s, RPM and More

Instant conversion between frequency units: hertz, kilohertz, megahertz, gigahertz, terahertz, radians per second, RPM and BPM. Formulas, reference values and conversion table included

Frequency Conversion
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Ratio: 1 MHz = 1,000 kHz · 1 GHz = 1,000 MHz · 1 Hz = 2π rad/s = 60 RPM
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Frequency Reference Values
AC power grid — 50 Hz (Europe) / 60 Hz (US)

Standard mains frequency in Europe, Africa, Asia and Australia is 50 Hz. North America and parts of Japan use 60 Hz. This is the frequency at which the voltage in a standard wall outlet oscillates. Plugging a 50 Hz appliance into a 60 Hz grid can damage motors

Human heartbeat at rest (~1.2 Hz)

A healthy resting heart beats 60–100 times per minute = 1–1.67 Hz. An ECG measures exactly this frequency with millihertz precision. Heart rate above 100 BPM (1.67 Hz) is tachycardia; below 60 BPM (1 Hz) is bradycardia

Human hearing range (20 Hz – 20 kHz)

The human ear detects sounds from 20 Hz (deepest bass) to 20,000 Hz (highest treble). Below 20 Hz is infrasound; above 20 kHz is ultrasound. Hearing loss typically starts from the top — adults often cannot hear above 14–16 kHz

AM radio (530–1700 kHz)

Amplitude modulation broadcasting uses the medium wave band: 530–1700 kHz. Long wavelengths allow signals to travel hundreds of miles, especially at night. Sound quality is lower than FM due to the narrow 10 kHz channel bandwidth

FM radio (88–108 MHz)

Frequency modulation broadcasting occupies the 88–108 MHz band worldwide. Stereo audio, wider 200 kHz channels, better sound quality than AM — but limited to line-of-sight propagation. A dipole antenna for 100 MHz is about 1.5 m long

Wi-Fi 2.4 GHz band

The most widely used Wi-Fi band. Better wall penetration than 5 GHz but more congested (Bluetooth, microwaves, and neighbors all share it). 2.4 GHz = 2,400 MHz = 2,400,000 kHz. Channels 1, 6 and 11 are the only non-overlapping ones

Wi-Fi 5 GHz band

Faster and less congested than 2.4 GHz. Used by Wi-Fi 5 (802.11ac) and Wi-Fi 6 (802.11ax). Shorter range due to higher frequency absorption by walls. 5 GHz = 5,000 MHz. Offers up to 23 non-overlapping 20 MHz channels

Modern CPU clock speed (~4 GHz)

Desktop and laptop processors run at 3–5 GHz — meaning 3–5 billion clock cycles per second. The overclocking world record in 2025 reached 9.12 GHz (AMD). Higher clock speed means more instructions per second, but also more heat and power consumption

Hard disk drive (HDD) at 7,200 RPM = 120 Hz

A 7,200 RPM hard drive spins its platters at 120 Hz. Slower 5,400 RPM drives spin at 90 Hz. Enterprise-grade 15,000 RPM drives reach 250 Hz. Rotational speed directly affects latency — faster spin means the read head waits less for data to pass underneath

Medical ultrasound (2–18 MHz)

Diagnostic ultrasound uses 2–18 MHz. Higher frequency = sharper image but shallower penetration. Abdominal scans use 3.5–5 MHz; superficial imaging (skin, thyroid) uses 7–18 MHz. Frequencies above 20 kHz are already inaudible — medical ultrasound is millions of times higher

Frequency Units Explained
Hertz (Hz)

The SI base unit of frequency. 1 Hz = 1 cycle per second = 1 s⁻¹. Named after German physicist Heinrich Hertz, who first demonstrated radio waves in 1887. Used for any periodic process: sound, AC voltage, oscillations, electromagnetic waves. Sub-multiples include millihertz (mHz) for very slow cycles like tides or heartbeats

Kilohertz / Megahertz / Gigahertz

1 kHz = 1,000 Hz · 1 MHz = 1,000,000 Hz · 1 GHz = 1,000,000,000 Hz. Kilohertz covers audio and AM radio. Megahertz covers FM radio, mobile networks and older CPUs. Gigahertz covers modern processors, Wi-Fi, 4G/5G. Each step up is a factor of 1,000

Terahertz (THz)

1 THz = 10¹² Hz = 1,000 GHz. Sits between microwave and infrared on the electromagnetic spectrum. Used in airport security scanners, spectroscopy, and medical imaging. Difficult to generate and detect with conventional electronics — often called the "terahertz gap." Being explored for future 6G communications

Radian per second (rad/s)

Unit of angular (cyclic) frequency ω. Relation to Hz: ω = 2π · f, so 1 Hz = 2π ≈ 6.2832 rad/s. To convert rad/s to Hz: divide by 2π. Used in electrical engineering, AC circuit analysis and mechanical vibration. For 60 Hz mains: ω = 2π × 60 ≈ 377 rad/s

Revolution per minute (RPM)

Unit of rotational frequency. 1 RPM = 1/60 Hz ≈ 0.01667 Hz. Conversely, 1 Hz = 60 RPM. Used for engines, motors, turbines, fans and hard drives. Car engine idle: ~800 RPM = 13.3 Hz. Redline: 6,000–8,000 RPM = 100–133 Hz. F1 engine: up to 18,000 RPM = 300 Hz

Beat per minute (BPM)

Numerically identical to RPM but used in medicine (heart rate) and music (tempo). Normal pulse: 60–100 BPM = 1–1.67 Hz. Music ranges from 60 BPM (slow ballad) to 200+ BPM (drum and bass). Standard dance music at 120 BPM = 2 Hz — exactly two beats per second

Frequently Asked Questions
How many Hz are in a kHz?

1 kHz = 1,000 Hz. To convert kHz to Hz multiply by 1,000. To convert Hz to kHz divide by 1,000. Example: 440 Hz (concert A note) = 0.44 kHz. 15 kHz (upper limit of audio) = 15,000 Hz.

How do I convert MHz to GHz?

Divide by 1,000. 1 GHz = 1,000 MHz. Example: 2,400 MHz = 2.4 GHz (Wi-Fi). 3,600 MHz = 3.6 GHz (CPU). To go the other way — multiply by 1,000: 5 GHz = 5,000 MHz.

How do I convert Hz to rad/s?

Multiply by 2π (≈ 6.2832). Formula: ω = 2π · f. Example: 60 Hz mains → ω = 2π × 60 ≈ 377 rad/s. To convert rad/s back to Hz: divide by 2π. Example: 100 rad/s ÷ 6.2832 ≈ 15.9 Hz.

How do I convert RPM to Hz?

Divide by 60. Formula: f (Hz) = RPM ÷ 60. Example: 3,000 RPM ÷ 60 = 50 Hz. 7,200 RPM ÷ 60 = 120 Hz. To convert Hz to RPM multiply by 60: 1 Hz = 60 RPM. Used for motors, engines and variable frequency drives (VFDs).

What is a hertz and what does it measure?

Hertz (Hz) is the SI unit of frequency. 1 Hz = 1 complete cycle per second. It measures any repeating event: sound wave oscillations, AC voltage cycles, CPU clock ticks, heartbeats, motor revolutions. Named after German physicist Heinrich Hertz (1857–1894).

What is the difference between Hz and rad/s?

Hz counts complete cycles per second. Rad/s measures how fast the phase angle changes (angular frequency). They describe the same oscillation differently. 1 Hz = 2π rad/s ≈ 6.2832 rad/s, because one full cycle = 2π radians. Engineers use rad/s in circuit equations; physicists and broadcasters use Hz.

What frequency is the power grid?

Europe, UK, Africa, Asia and Australia use 50 Hz. The United States, Canada and most of Central America use 60 Hz. Japan uses both — 50 Hz in the east and 60 Hz in the west. This difference matters for AC motors and some electronics without universal power supplies.

What unit is CPU clock speed measured in?

Gigahertz (GHz). Modern desktop CPUs run at 3–5 GHz, meaning 3–5 billion clock cycles per second. 1 GHz = 1,000 MHz = 1,000,000 kHz = 1,000,000,000 Hz. Higher clock speed generally means faster processing, but efficiency and architecture matter just as much.

Frequency Converter — How to Convert Frequency Units Online

Frequency measures how many times a periodic event repeats per second. The SI unit is the hertz (Hz), where 1 Hz equals one complete cycle per second. Different fields use different units: kilohertz and megahertz in radio and audio engineering, gigahertz in computing, radians per second in electrical circuit analysis, and RPM in mechanical engineering. Our online frequency converter handles all 10 units instantly, with no manual calculation needed.

How to Convert Hz to kHz, MHz and GHz

All SI frequency multiples follow powers of 1,000. To convert Hz to kHz divide by 1,000; to convert kHz to MHz divide by 1,000 again; MHz to GHz — same rule. Going the other direction, multiply by 1,000 at each step. For example: a CPU running at 3,600 MHz = 3.6 GHz; an FM station at 101.5 MHz = 101,500 kHz = 101,500,000 Hz. A quick mental shortcut — each step up the prefix ladder moves the decimal point three places to the left.

How to Convert Hz to rad/s and Back

Angular frequency ω (rad/s) and ordinary frequency f (Hz) describe the same oscillation in different ways. The formula is ω = 2π · f. To convert Hz to rad/s multiply by 2π ≈ 6.2832. To convert rad/s to Hz divide by 2π. Example: 60 Hz mains frequency → ω = 2π × 60 ≈ 377 rad/s. This conversion is essential in AC circuit analysis, control systems and mechanical vibration, where phase angles in radians are more natural than counting full cycles.

How to Convert RPM to Hz

Revolutions per minute and hertz are related by a factor of 60: f (Hz) = RPM ÷ 60, because there are 60 seconds in a minute. Conversely, 1 Hz = 60 RPM. Examples: a 3,000 RPM engine crankshaft spins at 50 Hz; a 7,200 RPM hard drive spins at 120 Hz; a 1 RPM clock second hand completes one revolution in 60 seconds = 1/60 Hz ≈ 0.0167 Hz. Variable frequency drives (VFDs) use this conversion constantly to control motor speed.

Frequency Ranges and Where They Are Used

Infrasound and low frequencies (below 20 Hz) — earthquakes, large machinery, infrasound weapons. Audio range (20 Hz – 20 kHz) — everything the human ear can detect. Radio frequencies (3 kHz – 300 GHz) — AM, FM, TV, mobile, Wi-Fi, radar. Microwaves (300 MHz – 300 GHz) — Wi-Fi, Bluetooth, satellite, microwave ovens. Terahertz (0.1–10 THz) — security scanners, spectroscopy, and the emerging 6G standard. Use the converter above to jump between any of these ranges instantly.

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