What this converter does
This converter turns a period in seconds into its frequency in hertz and back. Frequency is the reciprocal of the period: a shorter cycle time means a higher frequency. Enter a period and read the frequency instantly.
A 20-millisecond cycle is 50 Hz; a one-second cycle is 1 Hz. Useful for turning a measured cycle time into a rate.
The units it covers
Frequency and period are reciprocals — one is simply one divided by the other, so they are inversely related, not linked by a fixed factor.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| Frequency | Hz | f | Cycles per second |
| Period | s | T | Seconds for one cycle |
The formula
The period is one divided by the frequency, and the frequency is one divided by the period:
T = 1 ÷ fWhere:
- f = frequency in hertz
- T = period in seconds
Worked example
Find the frequency of a 20-millisecond period.
f = 1 ÷ T1 ÷ 0.02 = 50 HzSo a 20-millisecond cycle time is a frequency of 50 Hz.
The units in this example
The time for one cycle. A shorter period gives a higher frequency.
- 1 s = 1 Hz
- 20 ms = 50 Hz
- 16.7 ms ≈ 60 Hz
- 1 ms = 1 kHz
Cycles per second — the reciprocal of the period.
- 1 Hz = 1 s
- 50 Hz = 20 ms
- 1 kHz = 1 ms
- f = 1 ÷ T