RF Calculator
Perform common radio frequency calculations including wavelength, VSWR, and power conversions.
Wavelength from Frequency
VSWR from Forward and Reflected Power
dBm to Watts Conversion
RF Formulas
Key formulas used in radio frequency engineering.
Wavelength Calculation
Where c = speed of light (3 × 108 m/s), VF = velocity factor, f = frequency in Hz.
VSWR Calculation
Where Pf = Forward Power, Pr = Reflected Power.
dBm to Watts Conversion
Where P(W) is power in Watts, P(dBm) is power in dBm.
Common RF Applications and Frequencies
| Application | Typical Frequency Range |
|---|---|
| AM Radio | 535 kHz - 1.7 MHz |
| FM Radio | 88 MHz - 108 MHz |
| Wi-Fi (2.4 GHz) | 2.4 GHz - 2.5 GHz |
| Wi-Fi (5 GHz) | 5.1 GHz - 5.8 GHz |
| Bluetooth | 2.4 GHz - 2.485 GHz |
| GPS | 1.1 GHz - 1.6 GHz |
| Cellular (4G/5G) | 700 MHz - 6 GHz (varies by band) |
Frequently Asked Questions
What is RF?
RF stands for Radio Frequency, which refers to the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around 20 kHz to around 300 GHz.
What is VSWR?
VSWR stands for Voltage Standing Wave Ratio. It is a measure of how efficiently radio frequency power is transmitted from a power source, through a transmission line, into a load (e.g., an antenna). A VSWR of 1:1 indicates a perfect match, meaning all power is delivered to the load.
How is wavelength calculated in RF?
Wavelength (λ) is calculated by dividing the speed of light (c) by the frequency (f): λ = c / f. For practical purposes, especially with transmission lines, a velocity factor (VF) is often included: λ = (c × VF) / f.