radio & rf
Radio & RF Calculators
Free-space, impedance, and RF power calculations for station planning and bench reference.
power
dBm & RF Power
dBm is logarithmic: every 10 dB increase multiplies power by ten.
impedance
SWR & Return Loss
SWR must be at least 1:1. Return loss is entered as a positive dB value.
antenna
Antenna Starting Length
A factor of 0.95 is a practical starting allowance, not a universal wire velocity factor.