RF & Wireless Calculators
Free, practical calculators for the numbers behind a radio link — free-space path loss, link budgets, antenna gain, dBm and watts, wavelength and element lengths, and Shannon channel capacity. Educational engineering tools, not regulatory or design advice.
Free-Space Path Loss Calculator
Get the ideal line-of-sight loss in dB from a link's distance and frequency — the Friis baseline every link budget starts from, with unit conversion for km, miles, MHz, and GHz
RF Link Budget Calculator
Add transmit power and antenna gains, subtract path, cable, and fade losses, and compare against receiver sensitivity to see received power, link margin, and whether the link closes
Antenna Gain Converter
Convert antenna gain between dBi, dBd, and a linear power ratio, and estimate the half-power beamwidth of a symmetric beam — so two antennas compare on equal terms
dBm to Watt Converter
Convert RF power between dBm, milliwatts, and watts in either direction, with the log relationship that makes 0 dBm = 1 mW and 30 dBm = 1 W
Frequency & Wavelength Calculator
Turn a frequency into its wavelength and get half-wave and quarter-wave element lengths, with a velocity factor so a cut antenna element resonates on frequency
Shannon Channel Capacity Calculator
Compute the theoretical maximum error-free data rate from a channel's bandwidth and signal-to-noise ratio, plus the spectral efficiency in bits per second per hertz