Case 1
- Frequency (Hz)
- 50Hz
0.020000s
Open with these valuesFrequency to Period Calculator
0.020000s
Result: 0.020000 sPeriod and frequency are the same fact read from opposite ends: one counts cycles per second, the other measures how long one cycle takes. T = 1 / f, nothing else. Hertz in, seconds out — 50 Hz mains has a period of 0.02 s, which is 20 milliseconds.
Worked examples
Case 2
- Frequency (Hz)
- 60Hz
0.016667s
Open with these valuesCase 3
- Frequency (Hz)
- 1000Hz
0.001000s
Open with these valuesHow it's calculated
T = 1 / f
- StepEnter the frequency in hertz — 1 kHz is 1000, 1 MHz is 1000000.
- ResultRead the period in seconds; multiply by 1000 for milliseconds.
What this number means
Hertz in, seconds out
The field takes hertz and the answer comes back in seconds, so 1 kHz goes in as 1000 and 1 MHz as 1000000. Enter 1 for a kilohertz signal and the result lands three decades away, at 1 s instead of 0.001 s.
Milliseconds: multiply by 1000
50 Hz mains has a period of 0.02 s, which reads more easily as 20 ms. At 1 MHz the period is 0.000001 s.
Frequency and period are reciprocals
They describe the same oscillation from opposite ends, so their product is always one. 50 Hz pairs with 0.02 s, 0.5 Hz with 2 s, 1000 Hz with 0.001 s.
Angular frequency has its own page
ω = 2πf states the same rate in radians per second, because one full cycle is 2π radians. A 50 Hz signal has ω ≈ 314.16 rad/s. This page reports the period only.
Commonly misread
For 1 MHz I enter 1, because megahertz and microseconds pair up anyway.
The field is hertz: 1 MHz is 1000000 and its period is 0.000001 s. Entering 1 describes a one hertz signal, whose period is a full second.
Halving the frequency halves the period.
It doubles it. 1 Hz has a period of 1 s, and 0.5 Hz a period of 2 s.
50 Hz and 20 ms are two separate measurements of a signal.
They are one fact read from opposite ends, since 1 ÷ 50 = 0.02 s. Frequency counts cycles per second, the period measures how long a single cycle takes.
Reference table
| Frequency (Hz) | Where you meet it | Period (s) |
|---|---|---|
| 0.5 | One cycle every two seconds | 2.000000 |
| 1 | One cycle a second | 1.000000 |
| 50 | Mains power in Europe | 0.020000 |
| 60 | Mains power in North America | 0.016667 |
| 1000 | 1 kHz test tone | 0.001000 |
Questions
How do I calculate the period from a frequency?
Take the reciprocal of the frequency: T = 1 / f. Use hertz to get the period in seconds. A 50 Hz mains supply has a period of 1 ÷ 50 = 0.02 s, which is 20 milliseconds.
What is the period of a wave?
It is the time one full cycle of a repeating signal takes, measured in seconds. If something repeats 50 times a second, each cycle lasts one fiftieth of a second.
What is the difference between frequency and period?
They describe the same oscillation from opposite directions. Frequency counts cycles per second in hertz; period measures how long one cycle takes in seconds. They are reciprocals, so multiplying them always gives one.
What units should I use?
Enter hertz and read seconds. Multiply kilohertz by 1000 and megahertz by 1000000 before you start, or the answer lands in the wrong decade. A period below a millisecond is easier to read after multiplying by 1000.
What about angular frequency?
Angular frequency ω = 2πf expresses the same rate in radians per second instead of cycles per second, because one full cycle is 2π radians. A 50 Hz signal has ω ≈ 314.16 rad/s. It has its own calculator here rather than a second output on this page.
Sources and last check
Information, not professional advice.