Frequency to Period Converter
Convert any frequency in Hz, kHz, MHz, or GHz to its time period using T = 1/f. Output auto-scales to seconds, milliseconds, microseconds, or nanoseconds. Includes a visual single-cycle sine waveform, angular frequency, and wavelength.
Input
Result
Single-Cycle Sine Waveform
Frequency vs Period Reference
| Source / Application | Frequency | Period (T = 1/f) | Notes |
|---|---|---|---|
| Earth's rotation | ~11.6 µHz | ~86,400 s | 1 day = one period |
| Schumann resonance | 7.83 Hz | ~127.7 ms | Earth-ionosphere cavity |
| Sub-bass | 20 Hz | 50 ms | Lowest audible |
| Mains hum (EU) | 50 Hz | 20 ms | One cycle = 20 ms |
| Mains hum (US) | 60 Hz | ~16.667 ms | 1/60 s |
| Concert A4 | 440 Hz | ~2.273 ms | Standard tuning |
| 1 kHz audio test | 1,000 Hz | 1 ms exactly | Reference tone |
| Upper hearing limit | 20 kHz | 50 µs | Top of audible range |
| CD sample rate | 44.1 kHz | ~22.676 µs | Period between samples |
| AM radio | 1 MHz | 1 µs | Middle of AM band |
| FM broadcast | 100 MHz | 10 ns | Mid-FM |
| WiFi 2.4 GHz | 2.4 GHz | ~417 ps | One RF cycle |
| CPU clock 3 GHz | 3 GHz | ~333 ps | One clock tick |
| WiFi 5 GHz | 5 GHz | 200 ps | One RF cycle |
| 5G mmWave 28 GHz | 28 GHz | ~35.7 ps | One RF cycle |
About Frequency & Period
Use this frequency to period converter to find the time per cycle for any signal — essentially a frequency period calculator that works across Hz, kHz, MHz, and GHz. Period (T) is the time for one complete oscillation; frequency (f) is cycles per second. They are exact reciprocals: T = 1/f and f = 1/T. A 1 Hz signal has a 1-second period; a 1 kHz signal has a 1 ms period; a 1 GHz signal has a 1 ns period. When you need to go from Hz to time, you simply divide 1 by the frequency value. You can also reverse the calculation with the period-to-frequency converter if you're starting from a known time and need the equivalent frequency.
Why period matters in digital signals
Digital systems measure time in clock periods. A 3 GHz CPU has a clock period of ~333 picoseconds — every basic operation takes one or more of these ticks. Audio sample rates also work this way: 44.1 kHz means a sample every 22.676 µs, 48 kHz every 20.833 µs, 96 kHz every 10.417 µs. The duty cycle of a digital waveform is always expressed as a fraction of one period — a 50% duty cycle means the signal is high for exactly T/2. In analog instrumentation, period is also the quantity a frequency-to-voltage converter circuit implicitly measures: it integrates pulse count over time to produce a DC output proportional to frequency.
Why period matters in analog and RF
Oscilloscopes display signals in the time domain — they show period directly. A 1 MHz signal will fill one oscilloscope screen division (typically 1 µs/div) with one cycle. Period is the natural unit for measuring rise times, pulse widths, and signal timing. When you need a reference signal to compare against, you can generate a known-frequency tone and use its calculated period as your oscilloscope trigger reference.
Period and angular frequency
Mathematics often uses angular frequency (ω) instead of cyclic frequency in Hertz. The relationship is ω = 2πf (rad/s), and the time period of a wave in terms of angular frequency is T = 2π/ω. This is more natural for trigonometric functions: y = sin(ωt) completes one full cycle when ωt = 2π, i.e., when t = 2π/ω = T. The period of a wave and its wavelength are closely related: wavelength λ = v/f = v·T, where v is the propagation speed in the medium.
Worked Example: Converting Frequency to Period
The formula is T = 1 / f, where T is the period in seconds and f is the frequency in hertz. To convert 440 Hz (concert A4) to its period: T = 1 / 440 = 0.002272... s, which the tool scales to approximately 2.273 milliseconds. That is the exact duration of one complete oscillation of a vibrating A-string. The angular frequency for the same note is ω = 2π × 440 ≈ 2,765 rad/s, and its wavelength in air at 20°C is roughly 78 cm (speed of sound 343 m/s divided by 440 Hz).
Two clean reference values worth memorizing: 1 kHz → T = 1 ms exactly (useful as a mental anchor for audio work), and 1 MHz → T = 1 µs exactly (handy for RF and oscilloscope timing). Any other frequency can be estimated by scaling from these anchors. If you know a period instead of a frequency, use the period-to-frequency converter to invert the calculation.