📡 Frequency Unit Converter
A frequency converter across Hz, kHz, MHz, GHz, RPM and angular frequency, plus the period — all from one value, updating live.
What Frequency Unit Converter Does
Frequency is a count of cycles per second, and every unit on this page is that same count expressed a different way. Hertz is the SI base measurement. Kilohertz, megahertz and gigahertz are the same number of cycles per second scaled by the standard SI prefixes — 1,000, 1,000,000 and 1,000,000,000 respectively — the same prefixes used for bytes, watts and meters, not something specific to frequency.
Two of the units here describe the same physical thing in a different language rather than a different scale. Revolutions per minute counts the same cycles as Hertz, just per minute instead of per second, which is why 1 Hz is exactly 60 RPM. Angular frequency (radians per second) counts the angle swept through rather than the number of full turns, and one full turn is 2π radians — so it differs from Hz by a factor of 2π, not a power of ten.
Period is the odd one out: it is not a frequency at all, but its reciprocal — the time one cycle takes. A higher frequency is always a shorter period, and the relationship is exact: T = 1/f. This tool includes it because "what does 2.4 GHz mean in nanoseconds" is a real, common question, and computing period from frequency is a division most people would rather not do by hand.
How to Use Frequency Unit Converter
- Enter a value and choose which unit it is currently in
- Read the converted value in every other unit at once
- Switch the "From" unit to convert in the opposite direction instantly
Formula Used by Frequency Unit Converter
Converting through Hertz
Every unit converts to Hz first, then out to the target unit — never unit-to-unit directly
- kHz, MHz, GHz
- ×1,000, ×1,000,000, ×1,000,000,000 — standard SI prefixes
- RPM
- Hz × 60 (cycles per second → cycles per minute)
- rad/s
- Hz × 2π (cycles per second → radians swept per second)
Worked example
1,000 Hz, converted to every other unit
- kHz: 1,000 ÷ 1,000 = 1
- RPM: 1,000 × 60 = 60,000
- rad/s: 1,000 × 2π = 6,283.19
- Period: 1 ÷ 1,000 = 0.001 s
Result: 1 kHz, 60,000 RPM, 6,283.19 rad/s, and a period of 1 millisecond — all exactly the same underlying rate of change.
Frequency and period are reciprocals
T = 1 ÷ f f = 1 ÷ T
Worked example
FM radio at 100 MHz, and a musical A4 note at 440 Hz
- 100 MHz = 100,000,000 Hz → period = 1 ÷ 100,000,000 = 0.00000001 s = 10 nanoseconds
- 440 Hz → period = 1 ÷ 440 = 0.002273 s ≈ 2.27 milliseconds
Result: A radio wave completes a cycle roughly 227,000 times faster than a musical note most people can sing — the same math, wildly different time scales.
Frequencies people actually look up
Real-world reference points, so a converted number has something to compare against.
| Signal | Frequency | Period |
|---|---|---|
| Mains power (Europe, Asia, most of the world) | 50 Hz | 20 ms |
| Mains power (North America) | 60 Hz | 16.7 ms |
| Concert pitch A4 (musical tuning standard) | 440 Hz | 2.27 ms |
| FM radio band | 88–108 MHz | 9.3–11.4 ns |
| Wi-Fi (2.4 GHz band) | 2.4 GHz | ~0.417 ns |
| A modern CPU core clock | ~3–5 GHz | ~0.2–0.33 ns |
How to Read Your Result
RPM and Hz are the same measurement, different clock
Nothing physical changes between "10 Hz" and "600 RPM" — a fan spinning 10 times a second is doing exactly what a fan spinning 600 times a minute is doing. Engineering fields default to RPM for anything with a visible rotating part (engines, drives, disks) and Hz for anything electrical, purely by convention.
Angular frequency is what the math actually uses
Sine and cosine functions modeling oscillation are written in terms of ωt, not ft — angular frequency is the natural unit inside the mathematics, while Hz is the natural unit for describing what you would count with a stopwatch. The 2π factor is the cost of translating between the two.
Higher frequency always means shorter period, by definition
This is not an empirical observation, it is the reciprocal relationship itself: doubling frequency exactly halves period, and there is no scenario where a higher-frequency signal has a longer period. The reference table above shows this scaling all the way from a 20-millisecond mains cycle down to sub-nanosecond CPU clocks.
Limitations & Accuracy Notes
- This converts frequency units only. It does not compute wavelength, which additionally depends on the speed of the wave in its medium (this site's musical-note tool handles the sound-specific case).
- Extremely large or small results are shown in scientific notation past a threshold, since a number with dozens of digits is harder to read correctly than one written as a power of ten.
- RPM and Hz both assume a constant, steady rate. Neither this tool nor the underlying arithmetic accounts for acceleration or a rate that changes over the period being measured.
Frequently Asked Questions
How do I convert Hz to kHz?
How does RPM relate to Hz?
What is angular frequency and how is it different from Hz?
What is the period of a frequency?
Why does the period show ∞ for 0 Hz?
Is my data stored?
References & Further Reading
- BIPM — SI Prefixes — The International Bureau of Weights and Measures' official kilo/mega/giga definitions this converter uses