RF Toolbox puts 53 amateur radio and RF engineering calculators in one fast, offline-friendly app. Design antennas, check SWR, plan filters, read live solar indices and look up codes without switching between websites.
ANTENNA DESIGN
• Dipole, Inverted Vee, Vertical, Ground Plane and J-Pole calculators
• 3-Element Yagi and Full-Wave Loop
• Antenna Visualizer and SWR Chart
RF CALCULATORS & CONVERTERS
• VSWR, Decibel, Ohm's Law and Frequency / wavelength converter
• Coaxial cable properties and coax cable loss
• Doppler shift and unit converter
• Smith Chart: tap to place a point and read impedance, admittance and SWR
FILTERS & COMPONENTS
• Low-pass and high-pass filter design
• Reactance, inductor and air-core inductor calculators
PROPAGATION & TIME
• Solar & Propagation: live solar flux, K-index and A-index from NOAA SWPC with HF band condition estimates
• NVIS antenna planning, UTC world clock and contest timer
LOCATION
• GPS location with Maidenhead grid square
• Grid square, coordinate and distance tools
CODES & REFERENCE
• Q codes, RST, 92 codes, CW abbreviations and NATO phonetic alphabet
• Morse code translator and U.S. band plan
• Callsign prefix reference and a radio practice quiz
RF TOOLBOX PRO (one-time purchase)
Unlock 11 advanced tools with a single purchase. No subscription, and future Pro tools are included:
• 7-Element Yagi, Cubical Quad and Magnetic Loop
• Half-wave and narrowband balun calculators
• Pi and T attenuators, ERP / EIRP
• Link budget, RF exposure screening and radiation pattern
PRIVACY FIRST
• No account and no sign-in
• No ads and no analytics
• Favorites and calculation history stay on your device
• Location is used only when you open GPS Location and is not sent to our servers
Calculations and propagation estimates are planning aids. Always verify antenna safety, RF exposure compliance and your local regulations before transmitting.
Questions or feedback: tech@clk.company
53 ham radio and RF calculators: antennas, SWR, Smith chart, filters, solar data