AccelWare

Unit Conversion Tool - powerful, intuitive, and easy-to-use 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.

Analog Devices Assortment

Large list of applets for using their devices.

Antenna Design Calculator

By Q-par Angus.

Antenna Power Tools

Andrew's complete collection of antenna planning software.

Antenna System Evaluator

Evaluate consequences of SWR & feedline losses, KD6DKS.

Connect802 Antenna System Designer

An on-line calculator that creates a wireless network antenna system design report based on various parameters that you provide. It will help you predict end-to-end performance and evaluate your network design when you plan a point-to-point, or point-to-multipoint outdoor wireless network deployment. You'll be able to analyze the radio link and tune network parameters for optimal link suitability.

Antenna System Planner

By Andrew Corporation.

Astronomy

Kelper's 3rd Law, magnitude.

ATC Quick-Calc

Capacitor Calculation, American Technical Ceramics.

Attenuator Calculators

"T" and Pi topologies using online interactive Excel OWA technology. Here is a JavaScript version.

Attenuator Calculator

Four topologies: "T", Pi, Bridged-T, Reflection.

Attenuator Calculator

Very nicely done online interactive calculator - by Microwaves & RF, Paul Khanna of Phase Matrix

Attenuator Calculator
DK1RM

Here is a JavaScript version for Pi and T attenuators - auf Deutsch. Here it is in English. Other calculators available by clicking on the Tools link.

Attenuators

Minimum loss attenuator design.

AVX SPIMIC

Capacitor calculation.

Besser Associates
415-949-3300 / Los Altos, CA

Reflectometer, Butterworth Filter Designer,
dBm-to-dbW, and Smith Chart applets.

Broadcast Engineer's Calculators
by SOB (Sweet Old Bob)

HD cost estimates; Antenna, coax & other losses, Dual input HD Antenna TPO's; Convert units of Measure, High level combining; Look up ballpark coax loss & power ratings; Dehydrator size for up to 4 coax runs; Beam tilt and/or null fill Needed; STL path calculator for 950 paths; FM antennas; Gain of parabolic antenna; Channel vs. frequency; FM/TV; Plot Fresnel path; AM tower height & rigid coax; Power calculations; BTUs; Conduit size for your wire bundle; Does FM pattern meet FCC limits; Ohm's Law; Wire and circuit size for deicers; FCC Offical RFR Model Program Link

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.

Chris Gillings' Cardboard Slide Rule Collection

If you are at all nostalgic and also are a nerd, then you will drool over this collection by Chris Gillings. Andrew Antenna and Propagation Computer, Andrew Parabolic Antenna System Computer (1957), Andrew Parabolic Antenna System Computer (1964), Andrew Transmission Line Computer, BioMate, Blackwell Calculator, Althouse Chemical Co., Marconi Signal Source Calculator, Motorcraft Gasculator, National Standard Company Strip Calculator, Proportion Wheel, Radiac, No.1, Raytheon Radar Performance Calculator, Readymix Concrete Calculator, and many more. They're all here!

Compost

This is a handy, stand-alone calculator for attenuators, microstrip line parameters, microstrip filter synthesis, microstrip coupler synthesis, phase noise & jitter calculation w/chart, and VSWR calculator. Free and paid versions available. New - "Box-O-Volts" portable low-noise DC power supply. Brought to you by the Dizzy Farmer.

ConvertIt

Huge collection of converters and calculators.

Cubicle Quad Antenna Calculator

Determine dimensional quantities - javascript.

Daycounter, Inc. Engineering Services

Calculators for switching power supply, air core inductors, Sallen-Key LP Butterworth filter, L matching network, standard resistor value, PI & T pad attenuator, reactance, series - parallel impedance conversion, Z-S-Y 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

Die Temperature vs. Power Dissipation

An interactive calculator for estimating junction temperature from power dissipation and packaging/heatsink characteristics. By Analog Devices.

DigSim

Digital schematic editor & simulator from Berkeley.

eCalc

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

By Kirt Blattenberger.

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

Electric Field Units Converter

Online converter by Compliance Engineering. Wavelength to frequency, V/m to dBuV/m V/m dBuV/m, dBm to dBuV/m (50Ω), mW/cm^2 to W/m^2 (Free Space), mW/cm^2 to V/m (Free Space), mW/cm^2 to A/m (Free Space), mW/cm^2 to pJ/cm^2 (Free Space), W to dBm (50Ω), dBm to V (50Ω), V to dBm (50Ω)

Excalibur RPN Calculator Applet

Excalibur does not use more conventional "algebraic" notation like many low-end calculators on the market. Instead it uses the high-powered parenthesis-free RPN notation (Reverse Polish Notation).

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 finite-position transmission zeroes.

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

Free-Space Loss Calculator

Other calculators for

- Fresnel Clearance Zone

- EIRP

- Distance between two points using
   Latitudes and Longitudes

LC Filter Designer

From University of York.

Financial & Mortgage Calculators

Over 100 personal finance calculators.

Financial Calculators

Loan amortization, interest, loan payment by 1728 Software Systems.

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 interference-free 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 mid-point), the 60% (no obstacle) radius and the height of the earth curvature at the mid-point of the Total link distance. By Wireless Connections

Fresnel Zone Calculator

By itelite

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.

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

Wireline Calculator

Sage Wireline utility.

Wire Sizes

Calculate wire diameter, ampacity.

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.

J-Pole Antenna Calculator

Enter the operating frequency and calculate antenna dimensions - online.

Julian Date Calculator

Calculates JDs for a given month.

Karnaugh Map Calculator

By Russell Sasamori.

Karnaugh Minimizer

By Shurik Soft.

Javascript Planet

Large collection of JavaScripts.

Link Budget Calculator

A tower-to-tower, over-the-air JavaScript calculator, by Wireless Connections.

LOGInterMod
Leslie Green / U.K.

A Windows program (Freeware) that calculates two-tone intermodulation products up to the 30th order.

I Model It
415-568 2174 / San Francisco CA

A scientific library for electrical engineering, physics, astronomy, mathematics.

Look Angle Calculator

Use our look angle calculator to calculate the pointing angles your dish needs in order to receive a particular satellite.

Martindale's Calculator On-Line Center

More than 20,000 calculators - this site has grown incredibly over the years.

MegaConverter2

Multifunctional units converter.

Microwave Calculator

Free From JFW Industries.

Microwave Office

Combines an advanced IC and PCB layout editor with world-class circuit simulation and electromagnetic (EM) analysis tools by Applied Wave Research.

Mixer Spur Calculator

By Hittite Microwave.

Mortgage Calculator

8 different calculators: Mortgage calculator, Affordability, Early Pay-Off, Interest Only, Advanced Mortgage calculator, Mortgage Refinance, Basic Amortization, and Comparison calculator

MWI

Substrate line impedance calculator by Rogers Corporation.

MWIJ

The online version of MWI (microwave impedance calculator) written in Java - nice.

Online Conversion

Convert just about anything to just about anything else.

OpAmp Buffer Error Budget Calculator

This calculator has two parts: an annotated schematic at top and a table of contributing error sources at bottom - by Analog Devices.

OpAmp Gain Feedback-Input Resistor Calculator

Table of opamp feedback-input standard 5% tolerance resistor pairs that presents gain ratios. Two-resistor voltage dividers can also be specified and displayed in the table. Very clever cell shading scheme for indicating deviation from exact ratio that is specified. Provided by Mark Rushakoff.

OpAmp Parametric Evaluation Tool

Helps with the selection, evaluation and troubleshooting of voltage feedback opamps. It uses typical parametric data to mathematically model the general behavior of a selected amplifier - by Analog Devices.

Operational Amplifiers: Interactive Design Tools

Simple OpAmp Buffer Error Budget Calculator - from Analog Devices.

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; current-carrying capacity of traces and thermal vias; heat dissipation of thermal vias. By Sören Nilsson.

PCB Trace Width

Conductor thickness, ampacity, temperature rise.

PCB Trace Impedance Calculator

Online interactive calculator for stripline and microstrip, by U. of Missouri-Rolla EMC Lab.

PC Magazine Website

More than 140 free programs and calculators for electrical, civil, mechanical, and other engineering fields.

PDA Calculator Software

ADACS has a nice collection of software for engineering, scientific and financial applications.

Radiated Power Calculator: ERP, EIRP & dBuV/m
Compliance Engineering

Convert between Radiated Power Calculator: ERP, EIRP & dBuV/m

RF Calculators
by Phase Matrix, San Jose, CA

Here is a very nice collection of interactive calculators:  Tee & Pi Attenuators, Power to Voltage in a 50 ohm system, Converting dB to Ratio, mW to dBm, dBW, dBV & Volts in a 50 ohm system, Converting Phase Noise To Jitter (Part 1), Reflectometers Conversions: Interconverting VSWR, Return Loss, Reflection Coefficient and Mismatch Loss ,Designing Equal or Unequal Split Wilkinson Power Dividers, Cascading Three Stages for Gain, NF & P-1 dB, VSWR Mismatch Analysis and Power Uncertainty, Measuring Oscillator Output VSWR using Power Load Pulling, Microstrip Line Design, Designing Unequal Resistive Power Dividers/Couplers.

PLL Phase Noise Calculator

By Hittite Microwave.

Poles & Zeros Calculator

Move the poles and zeros to see the frequency domain response.

Power Calculator

Motor & line calculations, conversions.

Power Dissipation vs. Die Temperature Calculator

By Analog Devices.

Power Switch Designer

By Fairchild Semiconductor.

Power Supply

National's power supply design tool.

Power / Voltage / Current / EM Field Converter
Compliance Engineering

Converts between wavelength - frequency, volt/meter, amps/meter, watts - dBm, etc.

Power & Voltage Converter

Convert between units of dBm, dBW, watts,  dBV, volts.

PSI Select Pressurization Planner

Pressurization planner by Andrew Corporation.

Radiated Power Converter

Online converter by Compliance Engineering.

EIRP (mW) to ERP (mW) to dBuV/m @ 3m to dBuV/m @ 10m.

Radio Calculators

Pi attenuators and air inductor java calculators by Jim Hawkins.

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 non-inverting). Freeware.

RF Cafe Online Calculators

Many online calculators for noise figure/temperature, filter responses, voltage dividers, waveguide cutoff frequency, VSWR-return loss-reflection 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 Calculators

On the Federal Communications Commission website.

RF Cascade Workbook 2003

RF, system, cascade for Excel spreadsheet.

RF Cascade Workbook 2004

RF, system, cascade for Excel spreadsheet.

RF Cascade Workbook 2005

RF, system, cascade for Excel spreadsheet.

RF Workbench

RF, system, up/downconverter, spurious analysis, budget - best value out there.

RLC Tuned Circuit Calculator

Enter values for R, L, C, and/or frequency and it calculates the others

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).

RW Calc Software

Free from RadioWaves, several RF utilities, such as converters, far-field calculation, Fresnel zone clearance and free space propagation.

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.

SNR / THD / SINAD Calculator

By Analog Devices.

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.

Toroid Calculator

Uses standard cores; e.g., T-50.

Tower Planner

Andrew's handy calculator for height, wind speed, terrain, etc.

Transmission Line Calculator
The CircuitCalculator.com Website

Excel-based calculator

Transmission Line Calculator

By Kevin Schmit, W9CF.

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.

Units Converter: VRMS / dBm / dBu / dBV

A utility to convert between standard units of power measurement and signal strength - from Analog Devices

Voltage Divider Resistor Calculator

Table of two-resistor voltage dividers using standard 5% tolerance resistor. Opamp feedback-input resistor pairs can also be specified. Very clever cell shading scheme for indicating deviation from exact ratio that is specified. Provided by Mark Rushakoff.

Vrms / dBm / dBu / dBV Calculator

By Analog Devices.

VSWR Calculator

Animated version from BesserNet.

VSWR, Power Converter, Inductance Calculator
972-3-6175082 / 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.

- Parallel Plate Waveguide

- Rectangular Waveguide

- Dielectric Slab Waveguide

Waveguide & EM Calculators

This is a very nice Java/JavaScript-based set of calculators with a great user interface.

WiseCalc

WiseCalc is the complete mathematical text engine calculator for your computer.

- it's FREE!
- it has a multi-line text-editor type of interface
- it has 450+ unit conversions built-in
- it has hundreds of functions built-in
- it can save and open calculation pages
- it can evaluate built-in and user definable functions,
  units, constants, and matrices