Engineering Calculators & Converter Applets & Spreadsheets

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.
www.accelware.com

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.
www.alphimax.com/ptp

Antenna Design Calculator
The upper section relates antenna diameter and frequency to gain and beamwidth. Using the scroller, set the beamwidth against the 3 dB or 10 dB marker, and read off the corresponding frequency and diameter; or set the frequency against the diameter and read off the beamwidth. By Q-par Angus.
www.q-par.com/capabilities/software/microwave-antenna-calc-instructions

Antenna Power Tools
Andrew's complete collection of antenna planning software.
awapps.commscope.com/downloads

Antenna System Evaluator
Evaluate consequences of SWR & feedline losses, KD6DKS.
www.softcom.net/users/kd6dks/antenna.html

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 Official 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!

CoilSim
Basic ciol inductor calculator applet, by Nathan Iyer

Coordinate System Converter
Convert between rectangular, polar, spherical, and cylindrical coordinates.

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.

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.

Dizzy Farmer
Compost multi-purpose electrical engineering calculator/analysis/synthesis software. Resistive pi & Tee attenuator, microstrip line / coupler/ coupled-line, band-pass filter synthesis, phase noise analysis (integrated phase noise & jitter from plots), VSWR. Free & purchased versions.

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.ctromagnetic 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).

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.

Field Strength Calculator
V/m, dBuV/m, dBuA/m, pT, dBpT, Tesla, Guass, A/m, mW/cm^2 & W/m^2. From Compliance Engineering.

Filter Coupling Matrix Calculator
Facilitates synthesis of N+2 coupling matrices for Chebyshev bandpass filtering functions, with arbitrary finite-position transmission zeroes.

Filter Design Spreadsheets
Waveguide Filter Designer , Combline and Interdigital Filter Design Spreadsheet by 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.

Free-Space Loss Calculator
Other calculators for
- 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 interference-free wireless systems.

Fresnel Clearance Zone Calculator
By TeraBeam
www.terabeam.com/support/calculations/fresnel-zone.php

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.
www.wirelessconnections.net/calcs/FresnelZone.asp

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".
www.binarythings.com/hidigit

HP48 Calculator Programs
Lots of engineering programs.
www.hpcalc.org/hp48/science/electricity

Impedance Matching Network Designer
John Wetherell, Berkeley, CA.
www.sandiego.edu/~ekim/e194rfs01/jwmatcher

Inflation Calculator
U.S., Canadian, and Italian versions. Enter begin and end dates and get equivalent dollar values,
by S. Morgan Friedman.
www.westegg.com/inflation

J-Pole Antenna Calculator
Enter the operating frequency and calculate antenna dimensions - online.
www.hamuniverse.com/jpole.html

Julian Date Calculator
Calculates JDs for a given month.
www.1728.com/calendar.htm

Karnaugh Map Calculator
By Russell Sasamori.
puz.com/sw/karnaugh/kmap12.exe

Karnaugh Minimizer
By Shurik Soft.
karnaugh.shuriksoft.com

LC Filter Designer
From University of York.
http://www-users.cs.york.ac.uk/~fisher/lcfilter

Link Budget Calculator
A tower-to-tower, over-the-air JavaScript calculator, by Wireless Connections.
www.wirelessconnections.net/calcs/BudgetCalc.asp

LOGInterMod
Leslie Green / U.K.
A Windows program (Freeware) that calculates two-tone intermodulation products up to the 30th order.
www.logbook.freeserve.co.uk/

Look Angle Calculator
Use our look angle calculator to calculate the pointing angles your dish needs in order to receive a particular satellite.
www.intelsat.com/resources/satellitedata-pas/calc-look-angle.asp

Martindale's Calculator On-Line Center
More than 20,000 calculators - this site has grown incredibly over the years.
www.martindalecenter.com/Calculators.html

Math eBook
This website is fully interactive and will allow kids to practice and learn math with ease. It is designed to help students of different grades, starts from Kindergarten, Elementary, Middle School and High School Math. The goal of this website is to provide new education tools to teachers, parents and off course students who can benefit from it. Mathebook.net has Online Tutorials as well as Downloadable pdf tutorials.

MegaConverter2
Multifunctional units converter.

Microwave Calculator
Free From JFW Industries.

Microwave Impedance Calculator (MWIJ 1.0)
Substrate line impedance calculator by Rogers Corporation. Written in Java - nice.
Mixer Spur Calculator
By Hittite Microwave.

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 Pay-Off, Interest Only, Advanced Mortgage calculator, Mortgage Refinance, Basic Amortization, and Comparison calculator

Online Conversion
Convert just about anything to just about anything else.

OpAmp Gain Feedback-Input Resistor Calculator
GAIN-STAGE-CALC is a resistor selection tool for op amp gain stage. This KnowledgeBase Javascript calculator allows the designer to find the resistor values for both inverting and non-inverting op amp gain stages - with and without compensation for open-loop gain effects. By TI.
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.
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 Converter
Convert between units of dBm, dBW, watts,  dBV, volts.

Radiated Power Calculator
ERP, EIRP, dBuV/m, dBm & mW. From Compliance Engineering.

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.

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 Ratio Calculator
Finds R1/R2 combinations using standard resistor values, by Bennet Blake.

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 Calculator
Wavelength, dBm, dBuV, W, dBuV/m, mW/cm^2, pJ/cm^2, V & VSWR. From Compliance Engineering.

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, cross-talk, much more. By Amanogawa.

RF Calculators
On the Federal Communications Commission website.

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.

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. Also calculate capacitor and inductor impedance. Ohm's Law and RC time constant calculator.

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.

Sage Notebook
Spreadsheets for many realms of science and engineering. All are free downloads

Satellite-Related Calculators
Sun interference, power-to-noise, 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.

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.

TRL / LRL Calculator
TRL (Through, Reflect, Line) and LRL (Line, Reflect, Line) reference plane calculators provided by Electro-Photonics.

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

Vertex 42

Engineering calculators & converter applets & spreadsheets. Excel templates, financial calculators, and calendars. We also host The Excel Nexus - The ultimate directory of 3rd-party Microsoft Excel® resources, including add-ins, templates, tutorials, and consulting services.

Virtual Slide Rules
Standard slide rule - EngCom.net
Pickett slide rule - Antiquark.com

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.

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

Web Cool Tools
RF & microwave design applets that use numerical input or sliders for setting parameters.

WR-Connect
Waveguide structure design tool. Corrugated Low-Pass Filter Design Workshop.

Waveguide & EM Calculators
This is a very nice Java/JavaScript-based set of calculators with a great user interface.
Wireline Calculator
www.amanogawa.com/waves.html

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
www.wisecalc.com

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.