Frequency & Wavelength Calculator
Radio frequency and wavelength are related by the speed of light c = 299,792,458 m/s. Convert in both directions and get antenna reference dimensions (λ/4, λ/2).
Frequency, Period, Wavelength and Wave Speed
Convert frequency, period and wavelength with custom speed or air/water light and sound presets. Includes λ/2, λ/4 and λ/8.
Inputs and reverse calculation
Calculated results
| Frequency | 1 kHz |
|---|---|
| Period | 1 ms |
| Wave speed | 300 Mm/s |
| Wavelength λ | 300 km |
| λ/2 | 150 km |
| λ/4 | 75 km |
| λ/8 | 37.5 km |
How to interpret the result
A traveling wave obeys speed=frequency×wavelength. Period is the reciprocal of frequency. Changing speed preserves frequency and recalculates wavelength.
Formulas and units
T=1/f; λ=v/f; f=v/λ. Half-, quarter- and eighth-wave lengths are λ/2, λ/4 and λ/8.
Worked example
At 343 m/s and 1000 Hz, the period is 1 ms, wavelength is 0.343 m and λ/8 is 0.042875 m. The App light-in-air approximation of 3×10⁸ m/s gives 300 m at 1 MHz.
Scope and limitations
App presets are 3×10⁸ and 2.25×10⁸ m/s for light in air/water, and 343 and 1600 m/s for sound in air/water. The existing electromagnetic calculator uses vacuum c=299792458 m/s; these bases remain explicit. Medium, temperature and material affect speed; enter a custom value where needed. Inputs must be finite and positive. Fractional wavelengths are not physical antenna dimensions including dielectric and end effects.
Common questions
Why is frequency unchanged after a speed edit?
Following the App interaction, a speed edit preserves excitation frequency and changes wavelength. Editing wavelength recalculates frequency and period using the current speed.
Can I enter the exact vacuum speed of light?
Yes. Entering 299792458 m/s selects Custom; at 1 MHz the wavelength is 299.792458 m.
Related tools
Formula and data sources
Rebuilt from the extracted Electrodoc Pro 5.2 specification. Added, inferred and corrected behavior is identified in the limitations. Updated 2026-11-14.
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