Ham Radio & RF
Calculators for ham radio operators: dipole and vertical antenna length, dBm to watts, coax cable loss and SWR, with the RF formulas shown.
Coax Loss Calculator
Calculate total coax cable loss in dB from loss per 100 ft and run length, plus the power that reaches the antenna and the percent lost in the feedline.
dBm to Watts Calculator
Convert between dBm, watts and milliwatts. Enter any one value to get the other two RF power units instantly, with the conversion formula shown.
Dipole Antenna Calculator
Calculate the total length and each leg of a half-wave dipole antenna from frequency in MHz. Get the answer in feet and metres with the formula shown.
Quarter Wave Vertical Calculator
Calculate quarter-wave vertical and ground-plane antenna length from frequency in MHz. Get the radiator length in feet, metres and inches with the formula.
SWR Calculator
Calculate SWR from forward and reflected power, or from load and line impedance. Get the reflection coefficient, SWR and return loss in dB instantly.