Wavelength and Frequency Calculator
Fill in the values and the answer updates as you type.
How the Wavelength and Frequency Calculator works
Wavelength = speed of light ÷ frequency, with c = 299,792,458 m/s. This fits radio, light, and other electromagnetic waves travelling in a vacuum or air. Period = 1 ÷ frequency.
Inputs and results
The Wavelength and Frequency Calculator takes 2 inputs and gives 3 results.
What you enter
- Frequency — starts at 100.
- Unit — starts at MHz. Choose from: Hz, kHz, MHz and GHz.
What you get
- Wavelength (m)
- Wavelength (cm)
- Period (nanoseconds)
Example: Wavelength and Frequency Calculator with the starting values
With frequency 100 and unit MHz, the calculator returns:
| Wavelength (m) | 2.9979 |
|---|---|
| Wavelength (cm) | 299.7925 |
| Period (nanoseconds) | 10 |
Change any value above and the results update straight away.
Wavelength and Frequency Calculator FAQ
How do I use the Wavelength and Frequency Calculator?
Enter frequency and unit in the fields, then read wavelength (m), wavelength (cm) and period (nanoseconds) in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Wavelength and Frequency Calculator calculate?
Convert a wave frequency to wavelength using the speed of light. It returns wavelength (m), wavelength (cm) and period (nanoseconds) from the 2 values you provide.
What values does the Wavelength and Frequency Calculator start with?
It opens with frequency 100 and unit MHz so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Wavelength and Frequency Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Wavelength and Frequency Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.