Amateur Radio Calculators
Practical ham-radio tools for antenna dimensions, feedline planning, RF math, propagation estimates, and portable operating decisions from HF through UHF.
Amateur Radio Subcategory
Antenna Calculators
Start here for practical wire, loop, beam, gain, and matching tools including dipoles, verticals, Yagis, magnetic loops, and feed-point planning.
10 calculators
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Dipole Antenna Length Calculator
Calculate half-wave dipole total length, per-leg wire cuts, and practical wire-length corrections for HF ham-radio antennas.
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Vertical Antenna Calculator
Calculate quarter-wave and 5/8-wave vertical radiator length, radial length, and feed-point expectations for ham-radio antennas.
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J-Pole Antenna Calculator
Calculate J-pole radiator, matching stub, total conductor length, and feed-tap estimates for VHF and UHF ham-radio antennas.
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Yagi Antenna Calculator
Calculate Yagi reflector, driven element, director lengths, boom spacing, and rough gain for amateur-radio beam antennas.
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Ground Plane Antenna Calculator
Calculate quarter-wave ground-plane radiator, radial lengths by angle, and feed-point matching expectations for ham-radio antennas.
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Magnetic Loop Antenna Calculator
Estimate small-loop circumference, tuning capacitor range, bandwidth, Q, and efficiency for compact HF transmitting magnetic loops.
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Loop Antenna Calculator
Calculate full-wave loop circumference, side lengths, and feed guidance for square, delta, and quad-style ham-radio loop antennas.
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Beam Antenna Calculator
Estimate driven-element length, boom length, approximate gain, and front-to-back performance for amateur-radio beam antennas.
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Antenna Gain Calculator
Convert dBi and dBd, show linear gain, and estimate ERP and EIRP from transmitter power, feedline loss, and antenna gain.
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Antenna Impedance Matching Calculator
Compare quarter-wave transformer, L-network, and balun matching options for antenna impedance mismatches.
Amateur Radio Subcategory
Frequency and Wavelength
Convert between wavelength, frequency, and resonance so antenna dimensions and band planning stay grounded in the right math.
5 calculators
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Frequency to Wavelength Calculator
Convert amateur-radio frequencies into full-wave, half-wave, and quarter-wave dimensions in metres and feet with optional velocity-factor correction.
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Wavelength to Frequency Calculator
Convert a wavelength or physical line length in metres or feet into the equivalent amateur-radio frequency with optional velocity-factor correction.
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Resonant Frequency Calculator
Calculate resonant frequency for LC circuits and quarter-wave or half-wave amateur-radio antennas, with Q-factor and off-resonance context.
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Frequency Band Calculator
Identify the amateur band, sub-band use, allocation context, and practical operating notes for an entered US amateur-radio frequency.
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Doppler Shift Calculator
Calculate received-frequency offset from radial motion for amateur-radio satellite and moving-signal scenarios, including VFO correction direction.
Amateur Radio Subcategory
Power and Signal
Use these tools for dBm, watts, EIRP, SWR, path-loss, and received-signal planning across typical ham-radio station scenarios.
10 calculators
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RF Power to dBm Calculator
Convert amateur-radio transmitter power in watts into dBm, dBW, and milliwatt-scale reference values for link-budget and station planning.
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dBm to Watts Calculator
Convert dBm into watts, milliwatts, microvolts into 50 ohms, and approximate S-meter context for amateur-radio receive and transmit analysis.
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EIRP Calculator
Calculate effective isotropic radiated power from transmitter watts, antenna gain in dBi, and total system loss for amateur-radio station planning.
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SWR Calculator
Calculate standing wave ratio, return loss, mismatch loss, and delivered forward power from reflected-power percentage for amateur-radio troubleshooting.
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Reflection Coefficient Calculator
Calculate complex reflection coefficient, SWR, return loss, and mismatch loss from load impedance and system impedance for amateur-radio matching analysis.
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Path Loss Calculator
Calculate free-space path loss and total path attenuation for amateur-radio links using distance, frequency, and optional environmental loss.
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Link Budget Calculator
Calculate amateur-radio EIRP, path loss, received power, and link margin from station gain, loss, distance, and sensitivity inputs.
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Signal to Noise Ratio Calculator
Calculate signal-to-noise ratio, modeled receiver noise floor, and minimum detectable signal for amateur-radio modes and bandwidths.
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Noise Figure Calculator
Calculate single-stage and cascaded receiver noise figure, noise temperature, and system noise floor for amateur-radio receive chains.
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Transmitter Power Output Calculator
Calculate RF output, antenna-delivered power, and efficiency from wattmeter readings or DC input for amateur-radio transmitters.
About Amateur Radio Calculators
Amateur-radio planning questions often sit at the intersection of RF theory and real-world station compromises. A dipole that is perfect on paper still needs end-effect correction, a vertical that looks resonant still needs a practical radial system, and a portable POTA setup has to balance feedline loss, battery life, and deployment speed.
This category is built around those real decisions. The calculators focus on antenna dimensions, wavelength relationships, station-power math, and field-operating tradeoffs that hams actually use when building, tuning, and carrying gear into the field.