Frequency & Period Converter
Enter a frequency or a period value and instantly see the converted result. Supports automatic scaling between Hz, kHz, MHz, GHz and seconds, milliseconds, microseconds, nanoseconds.
Reviewed by the ToolNestr Editorial Team — July 2026
How frequency-period conversion works
Frequency (f) and period (T) are mathematically reciprocal: f = 1 / T and T = 1 / f. Frequency measures how many cycles occur per second (measured in hertz), while period measures the duration of one complete cycle. A 1 kHz signal completes 1000 cycles per second, so each cycle takes 1/1000 of a second (1 ms).
Common unit prefixes make it easy: 1 kHz = 1 ms period, 1 MHz = 1 μs period, 1 GHz = 1 ns period. Wavelength can also be calculated from frequency: λ = c / f, where c ≈ 3 × 108 m/s is the speed of light.
Worked example
What different frequency bands mean
The radio frequency spectrum is divided into bands with different propagation characteristics and applications.
RF Engineer
Convert between frequency, period and wavelength for antenna design, filter tuning and link budget calculations.
Ham Radio Operator
Quickly convert between amateur radio bands, calculate antenna lengths, and understand your operating frequencies.
Audio Engineer
Convert audio frequencies to periods for delay timing, reverb calculations, and digital audio workstation setups.
Student
Understand the fundamental relationship between frequency and period, and explore the electromagnetic spectrum.
| Frequency | Period | Wavelength | Band | Typical use |
|---|---|---|---|---|
| 50 Hz | 20.00 ms | 6000 km | SLF | Mains power |
| 1 kHz | 1.00 ms | 300 km | ULF | Audio test tone |
| 1 MHz | 1.00 µs | 300 m | MF | AM radio |
| 100 MHz | 10.00 ns | 3 m | VHF | FM radio |
| 1 GHz | 1.00 ns | 30 cm | UHF | Mobile phones |
| 10 GHz | 100 ps | 3 cm | SHF | Satellite / radar |
How to use the Frequency & Period Converter
Enter a value
Type a frequency or period value in either input field. The other field updates automatically in real time.
Select units
Choose the appropriate unit prefix for each value. All common scaling factors from Hz to GHz and ns to s are supported.
Read band and wavelength
The calculator identifies the frequency band and computes the free-space wavelength, useful for RF and antenna work.
Tips for working with frequency and period
Remember the reciprocal relationship
Frequency and period are always reciprocals. If you can remember one conversion (e.g., 1 MHz = 1 µs), you can derive the rest. 1 kHz = 1 ms, 1 GHz = 1 ns.
Use scientific notation for large ranges
When working across many orders of magnitude, use metric prefixes: 1 GHz = 10&sup9; Hz, 1 ns = 10&supmin;^9 s. This prevents errors from counting zeros.
Wavelength determines antenna size
A half-wave dipole antenna is approximately λ/2 long. For 100 MHz (λ = 3 m), a dipole is about 1.5 m. For 2.4 GHz (λ = 12.5 cm), it is only 6.25 cm.
Check units before calculating
Always verify that you are using consistent units. The calculator handles this automatically, but when doing your own math, convert everything to base Hz and seconds first.
The f = 1/T relationship
Frequency and period are mathematically reciprocal. If a signal completes 1000 cycles per second, its frequency is 1000 Hz (1 kHz) and each cycle takes 1/1000 of a second (1 ms). This relationship is fundamental to all time-varying signals in electronics, communications, and physics.
Unit prefixes explained
Metric prefixes allow convenient scaling: kilo (k = 10³), mega (M = 10&sup6;), giga (G = 10&sup9;). For period: milli (m = 10&supmin;^3), micro (µ = 10&supmin;^6), nano (n = 10&supmin;^9). Using the correct prefix avoids unwieldy numbers — 0.000000001 s is better written as 1 ns.
Wavelength formula λ = c / f
Wavelength is the physical distance a wave travels during one complete cycle. In free space, radio waves travel at the speed of light c ≈ 3 × 10&sup8; m/s. The wavelength is therefore λ = c / f. This is critical for antenna design: antennas are typically sized as fractions of a wavelength (λ/2, λ/4, etc.).
Applications across electronics
Frequency and period conversion is essential in countless applications: setting oscilloscope timebases, designing filters, calculating baud rates for serial communication, tuning radio receivers, specifying crystal oscillators, designing switching power supplies, and synchronizing digital systems. Every electronic device that uses a clock or a carrier wave relies on this fundamental relationship.
Frequently asked questions
What is the relationship between frequency and period?
Frequency (f) and period (T) are reciprocals: f = 1/T and T = 1/f. Frequency measures how many cycles occur per second (Hz), while period measures the time duration of one cycle. A higher frequency means a shorter period, and vice versa.
What are the common units for frequency?
Frequency is measured in hertz (Hz), where 1 Hz = 1 cycle per second. Common multiples are kHz (10³ Hz), MHz (10⁶ Hz), and GHz (10⁹ Hz). Radio frequencies range from kHz to GHz, while audio frequencies are typically 20 Hz to 20 kHz.
What are the common units for period?
Period is measured in seconds (s). For high frequencies, smaller units are used: milliseconds (ms = 10⁻³ s), microseconds (µs = 10⁻⁶ s), and nanoseconds (ns = 10⁻⁹ s). A 1 GHz signal has a period of 1 ns.
How do I convert frequency to wavelength?
Wavelength λ = c / f, where c is the speed of light (approximately 3 × 10⁸ m/s) and f is frequency in Hz. For example, 100 MHz has a wavelength of about 3 meters. Radio engineers often use this to determine antenna sizes.
What is the electromagnetic spectrum?
The electromagnetic spectrum spans from extremely low frequency (ELF, 3–30 Hz) through radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. This calculator covers the radio frequency range from ELF to SHF (up to 30 GHz).
What frequency bands are used for Wi-Fi?
Wi-Fi primarily uses two bands: 2.4 GHz (2400–2483.5 MHz) with longer range and better wall penetration, and 5 GHz (5150–5850 MHz) with higher speeds but shorter range. Wi-Fi 6E adds the 6 GHz band (5925–7125 MHz).
What is the frequency of AC power?
Mains AC power is 50 Hz in most of the world (Europe, Asia, Africa, Australia) and 60 Hz in North America and parts of South America. Some applications use 400 Hz for aerospace systems to reduce transformer weight.
How do I measure frequency with an oscilloscope?
Measure the time between two consecutive identical points on the waveform (e.g., zero crossing to zero crossing). This is the period T. Then calculate f = 1/T. Many oscilloscopes have automatic frequency measurement built in.
What is the difference between frequency and duty cycle?
Frequency is how often a cycle repeats. Duty cycle is the percentage of one period during which the signal is active (high). For example, a 1 kHz signal with 30% duty cycle is high for 0.3 ms and low for 0.7 ms of each 1 ms period.
Can I convert between any frequency and period units?
Yes. The calculator supports all common units: Hz, kHz, MHz, GHz for frequency and seconds, milliseconds, microseconds, nanoseconds for period. Enter any value in any unit and the corresponding period or frequency is automatically computed and displayed in all units.
Sources & references
This tool uses standard formulas and reference values from:
- • NFPA 70 — National Electrical Code (NEC), conduit fill, box fill and conductor ampacity. nfpa.org
- • IPC-2221, Generic Standard on Printed Board Design (trace width / current). ipc.org
- • NIST reference constants and unit definitions; IEEE standards where applicable. nist.gov
For educational and preliminary use. Verify against full engineering calculations and the governing standard before any real design.