This frequency converter converts hertz through gigahertz, RPM (rotations per minute), radians per second and cycle period — the units of audio, radio, motors and processors.
Frequency: How Often, In Every Dialect
The hertz is one cycle per second, scaled by SI prefixes into kHz (audio, radio AM), MHz (FM, older CPUs) and GHz (Wi-Fi, modern processors). Rotating machinery speaks RPM (÷ 60 = Hz), physics speaks rad/s (ω = 2πf), and engineers constantly invert to period T = 1/f — shown under every result. Frequency and wavelength trade through the speed of light/sound on our Wavelength Calculator. Part of our Conversion Calculators collection.
Quick Reference
| Thing | Frequency | Thing | Frequency |
|---|---|---|---|
| US mains power | 60 Hz (3,600 RPM equiv.) | Middle C (music) | 261.6 Hz |
| Human hearing | 20 Hz – 20 kHz | FM radio | 88–108 MHz |
| Car engine at redline | ~100–120 Hz (6,000–7,200 RPM) | Wi-Fi | 2.4 / 5 GHz |
| Vinyl LP | 0.556 Hz (33⅓ RPM) | Microwave oven | 2.45 GHz |
Worked Examples (Verified)
- 60 Hz mains = 3,600 cycles/minute and a period of 16.67 ms — the flicker clocks and zero-crossings of the grid
- A 7,200 RPM hard drive spins at 120 Hz — faster than your mains hum, which surprises everyone the first time
- 2.4 GHz Wi-Fi has a period of 0.42 nanoseconds per cycle — light travels 12.5 cm in that time (its wavelength, in fact)
Related Tools
- Wavelength Calculator — frequency’s wave partner
- Angle Converter — the turns inside rad/s
- Conversion Calculators — the full collection
Frequently Asked Questions
How do I convert RPM to Hz?
Divide by 60: 3,600 RPM = 60 Hz. Reverse, Hz × 60 = RPM. Engine, motor and turntable specs all bow to this one division.
How many Hz is a gigahertz?
One billion: 1 GHz = 10⁹ Hz = 1,000 MHz. Modern CPUs at 5 GHz cycle five billion times per second, each cycle lasting 0.2 ns.
What is the period of a 50 Hz signal?
T = 1/f = 20 ms (European mains). Period and frequency are reciprocals — the converter shows the period with every result.
Is rad/s a frequency?
It is angular frequency (ω), related by ω = 2πf: one full cycle (2π radians) per period. A 60 Hz signal has ω ≈ 377 rad/s. Converting Hz ↔ rad/s multiplies or divides by 2π ≈ 6.283.
What frequency is human hearing?
Roughly 20 Hz to 20 kHz for young ears, narrowing with age from the top down — the reason “mosquito tone” tests at 17 kHz work on teenagers and not their teachers.
Is this frequency converter free?
Yes — free, instant, no sign-up.