Hertz Calculator
Convert frequency between hertz (Hz), kilohertz (kHz), megahertz (MHz), gigahertz (GHz), period, RPM, and angular frequency. Enter one value, then click calculate.
What is hertz?
Hertz (Hz) is the standard unit of frequency. It tells you how many cycles happen each second. If something vibrates at 50 Hz, that means it completes 50 full cycles in one second. Frequency shows up everywhere: audio tones, electricity, radio waves, rotating machinery, and digital clocks.
How this hertz calculator works
This calculator converts different frequency formats into a common value in hertz, then derives related quantities automatically. It also computes wavelength when you provide wave speed.
- Hz, kHz, MHz, GHz are direct unit scales of frequency.
- Period (T) is the inverse of frequency:
f = 1 / T. - RPM converts through time:
f = RPM / 60. - Angular frequency uses radians per second:
ω = 2πf. - Wavelength is computed from speed:
λ = v / f.
Core formulas
1) Frequency and period
Frequency and period are inverses:
f = 1 / T and T = 1 / f
If a wave has a period of 0.02 s, its frequency is 50 Hz.
2) Frequency and RPM
Mechanical rotation is often measured in revolutions per minute:
f (Hz) = RPM / 60
A motor spinning at 1800 RPM runs at 30 Hz.
3) Frequency and angular frequency
For oscillations and AC circuits:
ω = 2πf and f = ω / (2π)
At 60 Hz, angular frequency is approximately 377 rad/s.
4) Frequency and wavelength
Given wave speed v and frequency f:
λ = v / f
For sound in air (about 343 m/s), a 343 Hz tone has a wavelength near 1 meter.
Common conversion references
- 1 kHz = 1,000 Hz
- 1 MHz = 1,000,000 Hz
- 1 GHz = 1,000,000,000 Hz
- 1 Hz = 60 RPM
Real-world examples
Audio engineering
Human hearing typically spans 20 Hz to 20 kHz. Bass frequencies are lower in Hz; treble frequencies are higher. Music producers constantly think in hertz for EQ, filters, and tone shaping.
Power systems
Electrical grids generally run at 50 Hz or 60 Hz depending on region. Equipment is designed around these standards, so frequency stability is critical.
Wireless and communications
Radio and network systems operate in kHz, MHz, and GHz ranges. For instance, Wi‑Fi and cellular standards are defined by frequency bands.
Mechanical systems
Rotating shafts, turbines, and fans are often measured in RPM. Converting to Hz helps when analyzing vibration and resonance.
Tips for accurate calculations
- Use consistent units before converting.
- Never enter zero for period if you need frequency (division by zero is undefined).
- Use realistic wave speed for wavelength (air, water, vacuum, etc.).
- For very large or very tiny values, scientific notation is normal.
Quick FAQ
Is Hz the same as cycles per second?
Yes. 1 Hz means 1 cycle every second.
What is the difference between Hz and rad/s?
Hz counts cycles per second, while rad/s counts radians per second. One cycle equals 2π radians.
Can I use this for sound and radio waves?
Absolutely. The same frequency math applies to many periodic systems.
Final thoughts
A good hertz calculator saves time and reduces conversion mistakes. Whether you're working with audio signals, rotating machines, AC circuits, or wave physics, knowing how to move between Hz, period, RPM, and wavelength gives you a strong practical edge.