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: October 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
- Enter a value.
- Choose the from and to units.
- Read the answer and the full table of equivalents below.
How frequency conversion works
| Term | Meaning |
|---|---|
| from-unit in Hz | Each unit’s definition in hertz (rpm ÷ 60 first). |
| to-unit in Hz | The 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
| Unit | Equals (Hz) | You meet it in |
|---|---|---|
| Hertz (Hz) | 1 | Sound, mains hum (50/60 Hz) |
| Kilohertz (kHz) | 1,000 | Audio range, AM radio |
| Megahertz (MHz) | 1,000,000 | FM radio, older CPUs |
| Gigahertz (GHz) | 1,000,000,000 | Wi-Fi, modern processors |
| rpm | 0.0167 | Engines, hard drives, turntables |
| Radian per second (rad/s) | 0.1592 | AC circuits, vibration analysis |
rpm to Hz at a glance
| rpm | Hz |
|---|---|
| 60 rpm | 1 Hz |
| 600 rpm | 10 Hz |
| 1,800 rpm | 30 Hz |
| 3,000 rpm | 50 Hz |
| 6,000 rpm | 100 Hz |
Hz = rpm ÷ 60; rpm = Hz × 60.
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.)
How do you convert Hz to kHz?
Divide the hertz value by 1,000 to get kilohertz: kHz = Hz / 1,000. So 5,000 Hz equals 5 kHz. The kilo prefix always means a factor of 1,000, and hertz measures cycles per second. To convert back, multiply kilohertz by 1,000 to return to hertz.
What is frequency measured in?
Frequency is measured in hertz (Hz), the SI unit named after Heinrich Hertz. One hertz equals one cycle per second. Related units scale by powers of 1,000: kilohertz (kHz), megahertz (MHz), and gigahertz (GHz) for higher frequencies, such as radio waves and computer processors.
How do I convert frequency to period?
They are reciprocals: f = 1/T and T = 1/f. A 60 Hz supply repeats every 1/60 s = 16.67 ms; a 1 kHz signal repeats every 1 ms. Our quick answer uses the same idea: 50 Hz mains repeats every 20 ms. Convert time units with our Time Converter.
How are Hz and rad/s related?
Angular frequency ω = 2π × f, so 1 Hz = 6.2832 rad/s. To go the other way, divide by 2π: 1 rad/s = 0.1592 Hz. Electronics and vibration analysis use rad/s; the converter handles both.
Sources
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.
Related tools
- Time Converter — period is 1/frequency, so frequency and time units pair naturally
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