Online Calculators for Radio and Electronic Design
Find a variety of online tools for calculating inductance, capacitance, impedance, resonant frequency, and RF safety for amateur radio projects.
Hams often need to calculate specific values for antenna projects, homebrew equipment, and station setup. These calculators help operators determine component values, analyze circuit behavior, and ensure compliance with technical regulations. From designing matching networks to evaluating RF safety, accurate calculations are essential for effective and safe amateur radio activity.
This category provides various online tools for common ham radio calculations. Operators can find resonant frequency calculators for LC circuits, impedance matching tools for antennas and feedlines, and inductance calculators for toroid and air-core coils. There are also specialized tools, such as the RF Safety Calculator from the University of Texas Amateur Radio Club, to help stations comply with power density limits, and the Mini Ring Core Calculator for toroid design.
Sort:
-
University of Texas Amateur Radio Club RF-Calculator. This is a main beam power density estimation program intended for use as part of a routine evaluation of RF safety compliance with FCC regulations -
Calculate the inductance of a single-layer, air-core coil. -
Online calculator, to convert dbWatts to Watts and vice-versa, or ERP and EIRP by G4URH -
Electrical and electronics online calculators by Calculatoredge.com -
Online impedance calculators grouped by types like Wire inductances, Toroid incuctances, Plane, PAD, Strap inductances, but even Core and Coax Inductances. Air core inductances and mutual inductance groups are also availbale. All these calculators let you input specific paramenters based on the inductor selected and will calculate specific incutance and related dimensions. -
LCF online Calculator, calculate relation between Frequency Capacitance Inductance and Reactance -
The easy way to calculate toroid cores. -
Online calculators for toroid coil, air-core coil inductance, XL, XC, and more. -
This web based application will compute circuit values required for an L-C circuit to resonate at given frequency. Also it will compute the resonant frequency if given values for L and C. -
This calculator is designed to give resistor values for unbalanced T-pads, and for balanced H-pads. -
Online calculator for Input coil data, LC Resonant Frequency and L match -
This page by ARCTICPEAK provides a calculator for determining ERP and EIRP (Effective radiated power and effective isotropic radiated power). The tool is designed to help hams calculate and understand the power radiated by their radio equipment. The content is useful for ham radio operators who want to optimize their transmission power and comply with regulations. LA8OKA Martin has created this resource to assist hams in accurately measuring their radio signals. -
Passive Bandpass Filter online calculator and filter formulas. Active Inverting Op Amp Bandpass Filters, Active Noninverting Op Amp Bandpass Filter, just enter the Low ir High Cutoff Frequency -
The dbm online calculator and reference table for 50 Ohm -
Passive Band-Pass Filter, low-pass filter calculator -
An online multiple calculator of 16 impedance matching networks -
This page by Arctic Peak provides a detailed explanation on how to use quarter-wave transmission lines as impedance transformers in ham radio antenna work. It explains how to match impedance values by connecting them with a λ/4 transmission line. The page also offers guidance on constructing your own transmission lines with specific impedance requirements, along with a calculator to determine the quarter wave length based on velocity factor and frequency. Useful for hams looking to optimize antenna performance and match transmission line impedance effectively. -
Online calculator that will convert power entered in milliwatts to dBm. Includes a quick mW to dBm conversion table -
dBm to watts conversion calculator and explaination on how to convert dBm to watts, including dBm to watts conversion table -
This website provide online calculator for several values about a large variety of toroids. Freq/L/C/Z/Turns Calculator, Impedance Matching Network Calculator -
This resistor calculation tool shows which combinations of two resistors, series or parallel, gives a match better than the closest standard value. -
If you need a non-standard resistor value you could probably realize a close match using two resistor. If you use two resistor in series it is quite easy to figure out which values give the best match; on the other hand, using a parallel connection it is not so easy (at least for me) to find a good combination. This resistor calculation tool shows which combinations of two resistors (series or parallel) gives a match better than the closest standard value, for the E12 (10%), E24 (5%) and E96 (1%) series. -
This is an on-line rf attenuator calculator provided free in order to promote the FLEXI-BOX. Calculates the resistor values, attenuation, minimum attenuation, impedance, reflection coefficient, VSWR and return loss of a matching Pi attenuator -
This calculator ask as input diameter, lenght turn and frequencu and will return L and Q -
This page provides a calculator to determine the total line loss and additional line loss in your transmission line based on the level of SWR. It helps hams understand the impact of high SWR on transmission line losses. The calculator allows users to input their SWR level and get accurate calculations of total losses. This tool is useful for ham radio operators looking to optimize their transmission setups and improve overall efficiency. -
Online variometer calculator by IN3OTD -
The page features a spreadsheet that calculates power in watt and dBm based on voltage and impedance, power in dBm with a given power and impedance, voltage in millivolts with a given power and impedance, and more. It also converts between millivolt, microvolt, volt, watt, and milliwatt. Useful for hams looking to accurately calculate power and voltage values for radio equipment. Last updated in December 2014.