Frequency measures how often something repeats per unit of time. The SI unit is the hertz (Hz), defined as one cycle per second and named after physicist Heinrich Hertz. Higher frequencies are expressed using metric prefixes — kilo (10³), mega (10⁶), giga (10⁹), tera (10¹²) — while rotating machinery often uses revolutions per minute (RPM), and physics uses angular frequency in radians per second.
Common Conversion Formulas
kHz → Hz: multiply by 1,000
MHz → kHz: multiply by 1,000
GHz → MHz: multiply by 1,000
RPM → Hz: divide by 60
Hz → RPM: multiply by 60
Hz → rad/s: multiply by 2π (≈ 6.2832)
rad/s → Hz: divide by 2π
Frequency Reference
Application
Typical frequency
Mains electricity (EU/Asia)
50 Hz
Mains electricity (US)
60 Hz
Human hearing range
20 Hz – 20 kHz
AM radio
535 – 1,605 kHz
FM radio
87.5 – 108 MHz
Wi-Fi (2.4 / 5 GHz)
2.4 – 5.8 GHz
Modern CPU clock
3 – 5 GHz
Car engine idle
600 – 1,000 RPM
Common Use Cases
Electronics: Specifying oscillator and clock speeds, radio bands, signal processing.
Frequency Converter is a free browser tool from SimpleCounter. Free frequency converter. Convert hertz, kilohertz, megahertz, gigahertz, RPM and radians/second instantly online. Enter your values and the result updates as you type — there is nothing to install and no account to create.
Definition: Frequency Converter
A frequency converter takes the numbers you enter and returns the result using the standard formula for that calculation, so you do not have to work it out by hand.
Key facts
Key facts about Frequency Converter
Cost
Free, with no account and no usage limit.
Where the maths happens
In your browser. The values you type are not sent to a server.
Devices
Any modern browser on phone, tablet, laptop or desktop.
Accuracy
Standard published formulas, shown with the units you selected.
Intended use
Estimates for everyday and educational use, not professional advice.
How to use the frequency converter
Type your value into the first field.
Choose the unit or option that matches your figures, if the tool offers a choice.
Read the result — it recalculates immediately, with no submit button.
Change any input to compare a second scenario side by side.
Disclaimer: This tool is provided for educational and informational purposes only. Results are estimates based on standard formulas and the inputs you provide. For financial, medical, legal, or tax decisions, consult a qualified professional. See our full disclaimer.
Frequently Asked Questions
How many kHz are in 1 MHz?
1 MHz equals 1,000 kHz, and 1 GHz equals 1,000 MHz. Each step up the SI prefix ladder multiplies by 1,000.
How do you convert RPM to Hz?
Divide RPM by 60, because there are 60 seconds in a minute. Example: 3,000 RPM ÷ 60 = 50 Hz. To convert Hz to RPM, multiply by 60.
What is the relationship between Hz and radians per second?
1 Hz equals 2π radians/s (approximately 6.2832 rad/s). Angular frequency ω = 2π × f, where f is in Hz.
What frequency is FM radio?
FM radio in most countries broadcasts between 87.5 MHz and 108.0 MHz. AM radio sits much lower, between 535 kHz and 1,605 kHz.
What does a 3.6 GHz CPU mean?
A 3.6 GHz CPU completes 3.6 billion clock cycles per second. Real performance also depends on cores, cache, and architecture — clock speed alone isn't the full picture.
Why is mains electricity 50 or 60 Hz?
Most of the world uses 50 Hz (Europe, Asia, Africa, Australia). North and parts of South America use 60 Hz. The choice is historical and roughly arbitrary — both work fine, but motors and clocks are designed for one or the other.
Benefits of using the Frequency Converter
What you actually get compared with a mechanical clicker, a notes app, or trying to hold the number in your head.
Nothing to install, nothing to sign up for
Open the frequency converter and start counting in the same second. No account, no email, no trial.
Your count survives real life
Totals are saved on your device as you go, so a locked screen, a closed tab, or a lost signal does not reset anything.
Works offline once loaded
Install it to your home screen and it keeps working in a warehouse, a pool hall, a field, or a plane — no connection needed.
Private by default
Counts stay in your browser. There is no cloud sync, no profile, and nothing about what you count is sent to us.
Free, with no sign-up
Works offline once loaded
Counts stay on your device
Installable as an app
Runs in your browser — nothing to download
72+ counter types available
Share your setup
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