These calculators are offered free of charge
 some by vendors and others by individuals. Some are standalone and others function
online via Java from the web page. The majority are engineering calculators, but
some are scientific calculators, some are amateur radio calculators, and some are
electrician type calculators.
See also the RF Cafe
Online Calculators and vintage
Cardboard Slide Rule Calculators.
A good way to find on this page what you need is do
a browser page search.
AccelWare
Unit Conversion Tool  powerful, intuitive, and easytouse utility for quick and
accurate conversion between almost every possible unit of measure, from one system
to another. The latest version includes more than 2200 units in 78 categories. The
categories include: length, area, speed, mass, numbers, volume, time, density, force,
pressure, energy, power, flow, temperature, angle, light, fractions, data transfer,
and many more. Fully functional Online version now available.
All About
Circuits This is a nice assortment (83 at
this time) of electrical & electronics parameter calculators, with a
couple mechanical types as well. There are many types of substrate impedance and
line dimension calculators, and calculators for voltage dividers, inductance and
capacitance, coax lines and waveguides, amplifiers, impedance matching, free space
loss, EIRP, radar range, and noise figure.
AlphiMAX
P2P Signal Propagation Calculator A very nice graphical interface
tools that enables you to compare manufacturers, while taking into account the terrain
of your area, terrain type, climate, antenna type, define fade margin and more.
Use of a GPS database produces a very accurate elevation profile between antenna
locations.
Analog Devices Calculators
Big list of online calculators
Antenna System Evaluator Evaluate consequences of
SWR & feedline losses, KD6DKS.
ATC TechSelect Capacitor Calculation, American Technical
Ceramics.
Attenuator
Calculators "T" and Pi topologies using online interactive Excel
OWA technology.
Attenuator Calculator Four
topologies: "T", Pi, BridgedT, Reflection.
Attenuator Calculator DK1RM Here
is a JavaScript version for Pi and T attenuators  auf Deutsch.
Attenuators Minimum loss attenuator
design.
Besser Associates
4159493300 / Los Altos, CA
Broadcast Engineering Related Calculators
Allen's Broadcast Engineering Extravaganza Lots of good JavaScript calculators:
AM Common Point / Antenna Current Calculator, FM Transmitter Power Output Calculator,
RPU/STL Transmitter Frequency Tolerance Calculator, AM Transmitter Harmonics Calculator,
Free Space Loss Between Isotropic Radiators Calculator, 0.6 First Fresnel Radius
Zone Calculator, VSWR Calculator, Coaxial Cable Loss Calculator, Coax Cable Loss/Antenna
Gain Calculator, Opamp Gain Calculator
Cable Performance Calculators Calculate loss &
power, VSWR & return loss, by Times Microwave.
Calc101
By webMathematica, scores of online interactive calculators for algebra, trigonometry,
calculus, matricies, linear equations.
Calculator Edge
This has to be one of the Web's largest collection of unique (as opposed to copied)
online calculators. Each of these topics has many calculators within them. General,
Civil Engineering, Optical Engineering, Mechanical Engineering, Plastics Engineering,
Metallurgy, Electronics Engineering, Electrical Engineering, Chemical Engineering,
Physics, Ceramics, Oil & Gas, Structural Engineering.
CapCAD
Capacitor calculation, by Dielectric Laboratories.
Chemandy Electronics +62 31 8914627
/ Jawa Timur, Indonesia Large selection of online interactive calculators for
RF design, including attenuators, capacitance, resonance, RF traps, and microstrip
impedance. Design, development and small scale manufacture of simple RF and Audio
items. We also have the capability for ATE programming in Labview, HP/Agilent Vee
or Visual Basic, and can produce associated test jigs.
Chemistry Calculators
Boyle's Law, Charles' Law, STP, molar volume, etc, by 1728 Software Systems.
Choke Designer Inductor values using
standard cores.
Coordinate System Converter Convert
between rectangular, polar, spherical, and cylindrical coordinates.
Connect802 Antenna System Designer An online calculator that creates
a wireless network antenna system design report based on various parameters that
you provide. It will help you predict endtoend performance and evaluate your network
design when you plan a pointtopoint, or pointtomultipoint outdoor wireless network
deployment. You'll be able to analyze the radio link and tune network parameters
for optimal link suitability.
ConvertIt
Huge collection of converters and calculators.
Daycounter,
Inc. Engineering Services Calculators for switching power supply,
air core inductors, SallenKey LP Butterworth filter, L matching network, standard
resistor value, PI & T pad attenuator, reactance, series  parallel impedance
conversion, ZSY parameter conversion, Rollet Stability (K) Factor, complete RF
amplifier design & analysis, LC resonance.
Dielectric Constant of Water (Complex)
Calculates the real and imaginary parts of the dielectric constant for water, sung
temperature, salinity, and frequency. By Gareth Harris
Dirac Delta "Science and engineering
encyclopedia." Hundreds of JavaScript calculators, definitions, historical information,
etc.
eeWeb
Advanced features including support for complex numbers, unit conversion, base conversion,
and has a built in equation solver. eCalc is one of the best calculators on the
web and runs completely in your browser without requiring any special plugins. Electrical
engineers will find eCalc's complex math especially useful since it supports both
rectangular and polar formats. eCalc supports both RPN and Algebraic Input Modes.
engApplets
Java applets for engineering education.
Engineering Calculators on Educypedia
A pretty good collection of links to online calculators  satellites, attenuators,
Smith Chart, VSWR, free space loss, etc.
EIA Equipment Rack Stencils for Visio By Kirt
Blattenberger.
EIA Tube Bases for Visio
Electromagnetic Field Applets Very nice graphical output
and user interface, with animation. 
Wave Propagation 
Field Polarization 
Oblique Incidence 
Oblique Incidence on Lossy Medium

Parallel Plate Waveguide 
Rectangular Waveguide 
Dielectric Slab Waveguide everything
RF A nice collection of RF calculators. 
Attenuator Calculator 
Microstrip Impedance Calculator 
Coax Impedance Calculator 
Cascaded Noise Figure Calculator

Skin Depth Calculator 
Wavelength Calculator 
dBm to Watt Calculator 
Watt
to dBm Calculator
Excalibur RPN Calculator Applet Excalibur
does not use more conventional "algebraic" notation like many lowend calculators
on the market. Instead it uses the highpowered parenthesisfree RPN notation (Reverse
Polish Notation).
Fast Fourier Transform Calculator
Do an FFT by entering the time domain data in the Time Domain Data box with each
sample on a new line. For complex (I and Q) data, the real and imaginary components
should be on the same line separated by a comma. Do an Inverse FFT by entering the
frequency domain data in the Frequency Domain Data box with each sample on a new
line. For complex (I and Q) data, the real and imaginary components should be on
the same line separated by a comma.
Field Strength Calculator Enter frequency
and antenna gain, then any one of received power, electric field strength, magnetic
field strength, or power density and this calculates the others.
Filter Coupling Matrix
Calculator Facilitates synthesis of N+2 coupling matrices for Chebyshev
bandpass filtering functions, with arbitrary finiteposition transmission zeroes.
Filter Design Spreadsheets
Waveguide
Filter Designer
Combline
and Interdigital Filter Design Spreadsheet
RF Shop Financial &
Mortgage Calculators Over 100 personal finance calculators.
Financial Calculators
Loan amortization, interest, loan payment by 1728 Software Systems.
FM Antenna Calculator by ERI (Electronics
Research, Inc.) Plots FCC 60 dBu contours right on the page. Also many PDF files
with Engineering Tables: Geotechnical Investigations for Antenna Support Structures,
Classes of FM Stations, FM Broadcast Channels, AM Tower Heights by Frequency, 54
dBu Contour Distances, 60 dBu Contour Distances, Site Plot Plan, Wind Speed Map,
Ice Probability Map, Antenna Support Structure Design Radius of Curvature Requirement.
FreeSpace Loss Calculator
Fresnel Clearance
Zone EIRP
Distance between
two points using Latitudes and Longitudes
Flex
Analysis Evaluate thermal/mechanical performance of flex circuits
by Rogers Corporation.
Frequency Finder  Open TV Channel Applet Sennheiser searches the
FCC database for an open channel for running interferencefree wireless systems.
Fresnel Clearance Zone Calculator
By TeraBeam
Fresnel Zone Calculator The calculator
will generate the radius of the first Fresnel zone only (at the obstacle point or
the midpoint), the 60% (no obstacle) radius and the height of the earth curvature
at the midpoint of the Total link distance. By Wireless Connections.
HiDigit
Scientific calculator with extended capabilities. Advantages include a simple input
format even for the most complicated scientific formulas; i.e., enter "10pi" instead
of "10*pi" or complex numbers as "1+2i".
HP48 Calculator Programs Lots of engineering programs.
iCalculator Huge collection of online calculators for tax,
finance, math, engineering, mortgages, logistics, loans, budgets, conversions, sports &
health, statistics, mechanics, and other topics.
Impedance Matching Network Designer
John Wetherell, Berkeley, CA.
Inflation Calculator
U.S., Canadian, and Italian versions. Enter begin and end dates and get equivalent
dollar values, by S. Morgan Friedman.
Inflation Calculator U.S. Bureau of Labor Statistics (BLS).
JPole Antenna Calculator Enter the operating frequency
and calculate antenna dimensions  online.
Julian Date
Calculator Calculates JDs for a given month.
Link Budget Calculator A towertotower,
overtheair JavaScript calculator, by Wireless Connections.
LOGInterMod
Leslie Green / U.K.  A Windows program (Freeware) that calculates twotone intermodulation
products up to the 30th order.
Martindale's Calculator OnLine Center
More than 20,000 calculators  this site has grown incredibly over the years.
MegaConverter2
Multifunctional units converter.
Microwave
Impedance Calculator (MWIJ 1.0) Substrate line impedance calculator
by Rogers Corporation. Written in Java  nice.
Mortgage Calculators Large variety of financial calculators
for mortgages, principal calculation, cost per thousand, affordability, income requirements,
FHA, refinance, HELOC, loan comparison tools, points, rent vs buy, & more.
Mortgage Calculator
8 different calculators: Mortgage calculator, Affordability, Early PayOff, Interest
Only, Advanced Mortgage calculator, Mortgage Refinance, Basic Amortization, and
Comparison calculator
N Calculators
Electronic circuit design calculators can assist you to solve, analyze and determine
the circuit design with capacitors, inductors, resistors, diodes, transistors, etc.
Many other types of financial, mathematical, and science calculators.
Noise Figure <> Noise Temperature Calculator
Online Conversion
Convert just about anything to just about anything else.
PCB Trace &
Via Calculator A very complete set of online calculators for microstrip,
embedded, and differential microstrip impedance; stripline and differential stripline
impedance; stripline and microstrip crosstalk; currentcarrying capacity of traces
and thermal vias; heat dissipation of thermal vias. By Sören Nilsson.
PLL Phase Noise Calculator By Hittite
Microwave (now Analog Devices).
Poles & Zeros Calculator Move the poles
and zeros to see the frequency domain response.
Power Calculator Motor & line calculations,
conversions.
Radio
Calculators Pi attenuators and air inductor java calculators by
Jim Hawkins.
Random Science Tools and Calculators
The intention of this site is to produce scientific tools and calculators, and store
information which will be useful to scientists, engineers, students and enthusiasts.
Chemistry
Electronics
Math
Physics Resistor Color Code Calculator (Reversible)
This resistor color code calculator also provides a table of nearest standard values
of resistors for standard tolerances.
Resistor Ratio
Calculator Leslie Green / U.K. A resistive network calculator
for problems using two or three fixed resistors. You have to use standard values,
but you need some silly ratio like 3.245 V from a 10 V source. This program helps
you to pick the optimum resistor values for simple resistor dividers or opamps (inverting
and noninverting). Freeware.
RF Cafe Calculator Workbook Collection of
commonly used calculators including Attenuators, Bandpass Filters, Cascaded Components,
Coils / Inductors, DeltaWye (Resistors), Directional Couplers, Doppler Shift, Highpass
Filters, Lowpass Filters, Mixer Frequency Conversion, Near / Far Field, Noise FigureTemp,
Path Loss, 1Way, Path Loss, 2Way, Propagation Time, Radar Blind Speed, Radar Horizon
/ Line of Sight, Rectangular Cavity, Skin Depth, Smith Chart, VSWRRLGamma, Voltage
Divider, Voltages & Power  Vrms, Vavg, Vpk
RF Cafe Online
Calculators Many online calculators for noise figure/temperature,
filter responses, voltage dividers, waveguide cutoff frequency, VSWRreturn lossreflection
coefficient conversions and more, by Kirt Blattenberger.
RF Calc General purpose engineering calculator by
MilMega  includes table of physical constants, component parameter calculators
(capacitance, inductance, resonance, pads), multiple transmission line calculators.
RF & Analog Tutorials
w/Java Apps Website This is a VERY nice collection of Java applets
and some PDF format tutorials. Antenna patterns, waveguide modes, electromagnetic
wave fronts, interactive Smith chart, transmission lines, standing waves, resonant
circuits, radiation of wires, crosstalk, much more. By Amanogawa.
RF Cascade Workbook 2018 RF, system, cascade
for Excel spreadsheet.
RF Workbench RF, system, up/downconverter, spurious analysis,
budget  best value out there.
RPN Calculator
This handy Reverse
Polish Notation calculator was written by the infamous Kelly Painter. Note the logo
in the upper right corner (hover your cursor over it).
SatelliteRelated
Calculators Sun interference, powertonoise, tilt angle, antenna
gain and more than thirty other calculators.
Satellite
Link Budget Calculator Uplink/downlink calculator, Satellite Signals
site.
Signals &
Noise Java applet for exploring random processes.
Smith Chart for Visio
By Kirt Blattenberger.
Sunshine Design
Engineering Services Ramona, CA Design specialties  hardware,
CAD and software engineering. Test Engineering Services  20 years experience RF/Microwave
and Semiconductor Parametric Test. Electronic Calculator  Multiple pages of calculators
for capacitance, resistance, inductance, attenuation, microstrip, resonance, etc.
Many astronomical calculators.
SWR Calculator VNA Help  for microwave network
analyzers.
Transmission Line Calculator The
CircuitCalculator.com Website Excelbased calculator
TRL / LRL Calculator TRL (Through,
Reflect, Line) and LRL (Line, Reflect, Line) reference plane calculators provided
by ElectroPhotonics.
TXLine
Transmission Line Calculator by Applied Wave Research. This file seems to be no
longer available on the AWR website.
Ultra Converter
I Ultra Converter
II If these to converters don't have it, you don't need to convert
it! by 1728 Software.
Unit
Converter This is a very extensive measurement value and units
converter for length, weight, height, area, temperature, time, pressure, speed,
force, etc. Each and every converter has a detailed explanation with an example.
Vertex 42 
Engineering calculators & converter applets & spreadsheets.
Voltage Divider Resistor Calculator
Table of tworesistor voltage dividers using standard 5% tolerance resistor. Opamp
feedbackinput resistor pairs can also be specified. Very clever cell shading scheme
for indicating deviation from exact ratio that is specified. Provided by Mark Rushakoff.
VSWR, Power Converter, Inductance Calculator
97236175082 / Israel Free downloadable VSWR, power converter, inductance calculator,
written by Dr. Ronen Holtzman for Elisra Microwave Division engineers.
Waveguide Filter
Dimension and Electrical Response Calculator By Guided Wave Technology.
Waveguide Applets Very nice graphical output and user interface,
with animation.
Web Cool Tools RF & microwave
design applets that use numerical input or sliders for setting parameters.
WRConnect
Waveguide structure design tool.
Corrugated
LowPass Filter Design Workshop
Waveguide & EM Calculators This is a very nice
Java/JavaScriptbased set of calculators with a great user interface.
Wireline Calculator
WLAN Link Planning Calculators Many
calculators for wireless link planning: Fresnel zone, diffraction, path loss, link
budget, cable loss.
Yagi Java Applet Change frequency,
element diameter, and number of segments.
