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Frequency Converter (Hz, kHz, MHz, GHz)

Quick answer: Frequency is the number of repeating cycles per second, measured in hertz. One kilohertz is 1000 Hz, one megahertz a million, one gigahertz a billion. Period and frequency are reciprocals: a 50 Hz mains supply repeats every 20 milliseconds. This converter also handles RPM, where 60 RPM equals 1 Hz.

Last reviewed: September 2026

Key facts

  • 1 GHz = 1,000 MHz = 1,000,000,000 Hz. Each step up multiplies by 1,000.
  • Concert pitch A4 is 440 Hz; middle C is about 261.63 Hz.
  • Human hearing spans roughly 20 Hz to 20,000 Hz.
  • 1 rpm = 1/60 Hz — revolutions per minute is a frequency too.

Radio stations, Wi-Fi, processor speeds and engine revs all quote frequencies — in Hz, kHz, MHz, GHz or rpm. This free frequency converter moves between them all instantly.

Enter a value and pick your units. Frequency is simply cycles per second, so converting is a clean powers-of-ten shift — with rpm folded in via 1 rpm = 1/60 Hz.

How to use

  1. Enter a value.
  2. Choose the from and to units.
  3. Read the answer and the full table of equivalents below.

How frequency conversion works

result = value × (from-unit in Hz ÷ to-unit in Hz)
TermMeaning
from-unit in HzEach unit’s definition in hertz (rpm ÷ 60 first).
to-unit in HzThe target unit’s definition in hertz.

Hertz means “cycles per second”. Kilo, mega and giga are the standard metric prefixes: ×1,000 each step.

Worked examples

Wireless tech

2.4 GHz Wi-Fi → MHz: 2.4 × 1,000 = 2,400 MHz.

101.5 MHz FM station → Hz: 101.5 × 1,000,000 = 101,500,000 Hz.

Sound and spin

Concert A 440 Hz → kHz: 440 ÷ 1,000 = 0.44 kHz.

3,000 rpm engine → Hz: 3,000 ÷ 60 = 50 Hz — the crankshaft turns 50 times per second.

Frequency units and landmarks

UnitEquals (Hz)You meet it in
Hertz (Hz)1Sound, mains hum (50/60 Hz)
Kilohertz (kHz)1,000Audio range, AM radio
Megahertz (MHz)1,000,000FM radio, older CPUs
Gigahertz (GHz)1,000,000,000Wi-Fi, modern processors
rpm0.0167Engines, hard drives, turntables

Landmarks: human hearing 20–20,000 Hz · concert A 440 Hz · FM band 88–108 MHz · Wi-Fi 2.4 / 5 GHz.

Frequently asked questions

What does Hz actually mean?

Hertz = cycles per second. 440 Hz means something vibrates 440 times each second — the A above middle C.

How do rpm convert to Hz?

Divide by 60: 3,000 rpm = 50 Hz. Multiply Hz by 60 to go back.

Why is FM radio in MHz?

FM stations broadcast at 88–108 million cycles per second — 88–108 MHz. AM radio is lower, around 0.5–1.7 MHz.

What frequencies can humans hear?

Roughly 20 Hz to 20,000 Hz, shrinking with age — most adults top out well below 20 kHz.

Why are CPU speeds in GHz?

A 3 GHz processor ticks 3 billion cycles per second. (Clock speed isn’t everything — work per tick matters too.)

Sources

  • NIST — Frequency measurement standards
  • BIPM — Defines the hertz as the SI unit

Key takeaways

  • kHz → MHz → GHz: ×1,000 each step; 1 rpm = 1/60 Hz.
  • 440 Hz = concert A; 20–20,000 Hz ≈ human hearing.
  • FM 88–108 MHz, Wi-Fi 2.4/5 GHz — now you can read the dial.

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