Frequency Converter

Convert between hertz, RPM, and other frequency units

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About Frequency Converter

Understanding Frequency

Frequency measures the number of occurrences of a repeating event per unit of time. The standard SI unit is the hertz (Hz), defined as one cycle per second. This fundamental concept appears throughout science and engineering, from electronic signals to mechanical rotations. Heinrich Hertz's groundbreaking experiments with radio waves in the 1880s led to the unit being named in his honor. Today, frequency measurements are crucial in fields ranging from telecommunications to music, and from quantum physics to astronomy.

Common Applications

Application	Typical Range	Unit
Human Hearing	20-20,000	Hz
CPU Clock	2-5	GHz
Hard Drive	5400-7200	RPM
Radio FM	88-108	MHz

Unit Relationships

SI Prefixes

1 kHz = 1,000 Hz
1 MHz = 1,000 kHz
1 GHz = 1,000 MHz
1 THz = 1,000 GHz

Other Conversions

1 Hz = 60 RPM
1 Hz = 6.28319 rad/s
1 Hz = 3600 cycles/hour
1 Hz = 60 BPM

Electromagnetic Spectrum

Frequency Bands

Radio Waves: 3 Hz - 300 GHz
Microwaves: 300 MHz - 300 GHz
Infrared: 300 GHz - 430 THz
Visible Light: 430-750 THz
Ultraviolet: 750 THz - 30 PHz
X-rays: 30 PHz - 30 EHz
Gamma Rays: > 30 EHz

Musical Frequencies

Musical Notes

A4 (concert pitch): 440 Hz
Middle C (C4): 261.63 Hz
Lowest piano note (A0): 27.5 Hz
Highest piano note (C8): 4186 Hz

Natural Frequencies

Biological and Natural Cycles

Heart Rate: 60-100 BPM
Brain Waves: 0.5-100 Hz
Circadian Rhythm: ~1 cycle/day
Lunar Cycle: ~1 cycle/month
Earth's Rotation: 1 cycle/day

Learn More

NIST Frequency Standards ITU Frequency Notation ISO Rotational Speed