9 Best Free Online Impedance Calculator Websites

Here is a list of best free online Impedance calculator websites. Impedance or Electrical Impedance is the effective resistance that a material imposes on the flow of alternating current. Impedance in alternative current is similar to resistance in direct current circuits. The calculation of impedance is important in various fields like Power Transfer, Filter Design, Antenna Design, etc. If you also want to calculate the electrical impedance in a conductor, then check out these online impedance calculator websites.

Through most of these websites, users can calculate the impedance of coaxial and twisted pair cables. Apart from impedance, they can also calculate reactance, inductance, delay, etc., wire parameters. To perform the calculation, users need to submit some known values like inner conductor diameter, substrate dielectric, separation between wires, etc. These calculators also explain impedance and show the impedance calculation formulas. To help new users, I have included the necessary calculation steps in the description of these websites.

These websites offer multiple online tools like Cable Impedance Calculator, Drone Flight Time Calculator, Circular Capacitor Calculator, Matching Pi Attenuator, and more. Go through the list to learn more about these calculators.

My Favorite Online Impedance Calculator Website:

omnicalculator.com is my favorite website as it can calculate the impedance of both Coaxial and Twisted Pair cables. It also shows the impedance calculation formula. Apart from impedance, it can also calculate Inductance, Capacitance, Delay, and Cutoff Frequency.

You can also check out lists of best free Online Noise Figure Calculator, Online RC Filter Calculator, and Online Azimuth Calculator websites.

Comparison Table:

Features/Website Names	Shows Calculation Formula	Can calculate impedance of multiple cables types	Can also calculate inductance and capacitance
omnicalculator.com	✓	✓	✓
calctool.org	✓	✓	✓
chemandy.com	✓	x	x (only capacitance)
allaboutcircuits.com	✓	x (only twisted pair)	✓
pasternack.com	✓	x (only coaxial)	✓
eeweb.com	✓	x (only twisted pair)	✓
newark.com	✓	x (only twisted pair)	✓
emclab.cei	✓	✓	x
everythingrf.com	✓	x (only coaxial)	✓

omnicalculator.com

omnicalculator.com is a free online impedance calculator website. Using this website, users can calculate the impedance of coaxial and twisted pair cables. For Coaxial cables, it needs inner conductor diameter, inner diameter of surface shield, and substrate dielectric values to calculate impedance. In the case of twisted pair cables, users need to submit wire diameter, separation between wires, and substrate dielectric values to calculate impedance value. Apart from impedance, it also calculates capacitance, delay, and inductance values.

This website guides users to properly use this calculator to obtain correct impedance values. It also explains impedance in detail and shows the impedance calculation formula. Now, check out the below steps.

How to calculate wire impedance online using omnicalculator.com:

Go to this website and open up the Impedance Calculator section.
After that, choose the Coaxial or Twisted Pair cable type.
Now, enter all the required input values and specify their SI units.
Finally, view the calculated impedance, capacitance, delay, and inductance values.

Additional Features:

This website offers related electronics calculators such as Amdahl’a Law, Cable Impedance, Drone Flight Time, Hamming Code Calculator, and more.

Final Thoughts:

It is a good online impedance calculator website that can calculate the impedance of coaxial and twisted pair cables.

Pros	Cons
Calculates impedance of coaxial and twisted pair cables
Can also calculate capacitance, inductance, and delay values
Shows calculation formula

Home Page

calctool.org

calctool.org is another free online impedance calculator website. This website not only calculates wire impedance but also explains it to users. It can perform both Coaxial and Twisted Wire impedance calculations. It also shows the formula that it uses to calculate the impedance value. I also like its ability to calculate other parameters like Wire Capacitance, Delay, Inductance, Cutoff Frequency, and more. Now, follow the below steps.

How to calculate wire impedance online using cactool.org:

Visit this website and access the Impedance Calculator.
After that, select either a Twisted Pair or Coaxial cable type.
Now, enter the required input values.
Next, view the calculated impedance, capacitance, delay, etc., values.

Additional Features:

This website offers multiple calculators associated with Optics, Relativity, Waves, Maths, etc., fields.

Final Thoughts:

It is another capable online impedance calculator website that anyone can use without much hassle.

Pros	Cons
Can also calculate the impedance of coaxial and twisted pair cables
Shows calculation formulas
Can calculate wire inductance, capacitance, and delay values

Home Page

chemandy.com

chemandy.com is another free online impedance calculator website. Using this website, users can calculate the impedance of round straight wire. It considers multiple wire materials in the calculation namely Gold, Copper, Aluminum, Silver, and Nickel. Besides this, users also need to submit Wire Frequency, Length, Diameter, and Relative Permeability of Insulator values. Apart from Impedance, it also calculates wire resistivity, skin effect depth, internal inductance, and external inductance values. This website shows all the formulas that it uses to calculate impedance and other associated parameters. Now, follow the below steps.

How to calculate impedance of a round straight wire online using chemandy.com:

Visit this website and access the impedance of a round straight wire.
Now, specify a wire conductor material.
Next, specify other wire parameters like frequency, length, diameter, etc.
After that, click on the Calculate button to start the calculation process.
Finally, view the calculated wire impedance value.

Additional Features:

This website offers multiple online tools like Flat Wire Inductor Calculator, Circular Capacitor Calculator, Matching Pi Attenuator, Rectangular Capacitor, etc.

Final Thoughts:

It is another good online impedance calculator website that helps users calculate the impedance of a round straight wire.

Pros	Cons
Can also calculate resistivity, skin depth effect, and internal inductance values
Shows calculation formula

Home Page

allaboutcircuits.com

allaboutcircuits.com is another free online impedance calculator website. This website offers a dedicated twisted pair impedance calculator through which users can calculate the impedance of twisted pair cables. To do that, users need to submit twisted pair wire parameters namely wire diameter, separation between wires, and substrate dielectric values. After performing the calculation, it shows wire impedance, delay, inductance per inch, and capacitance per inch values. It also highlights formulas that it uses in the calculation. Now, follow the below steps.

How to calculate wire impedance online using allaboutcircuits.com:

Visit this website using the given link.
After that, enter wire diameter, separation between wires, and substrate dielectric values.
Now, specify the wire diameter and separation between wire units.
Finally, click on the Calculate button to view the calculated impedance value.

Additional Features:

This website has multiple related calculators like Microstrip Impedance, Symmetric Stripline Impedance, Wire Stripline Impedance, etc.

Final Thoughts:

It is another good online wire impedance calculator website that works with twisted pair wires.

Pros	Cons
Also calculates delay, inductance, and capacitance values	Only calculates the impedance of twisted pair cables
Shows calculation formula

Home Page

pasternack.com

pasternack.com is another free online impedance calculator website. This website offers a simple coaxial cable impedance calculator. This calculator uses Dielectric Outer Diameter, Inner Conductor Diameter, and Dielectric Constant or Velocity of Propagation values to perform the calculation. Apart from wire impedance, it also calculates cutoff frequency, capacitance, and inductance values. It also shows the coaxial cable cross-section diagram and the impedance calculation formula. Now, follow the below steps.

How to calculate impedance of a coaxial wire online using pasternack.com:

Visit this website using the given link.
After that, submit dielectric outer diameter, inner conductor diameter, and dielectric constant or velocity of propagation value.
Next, click on the Calculate button to view the calculated impedance value.

Additional Features:

On this website, users can browse and purchase multiple RF products like RF Couplers, RF Detectors, RF Filters, RF Rotary Joints, RF Noise Sources, and more.

Final Thoughts:

It is another simple online impedance calculator that allows users to calculate impedance, capacitance, and cutoff frequency of coaxial wires.

Pros	Cons
Can also calculate cutoff frequency, inductance, and capacitance values	Only calculates the impedance of coaxial cables
Shows calculation formula

Home Page

eeweb.com

eeweb.com is another free online impedance calculator website. Through this website, users can calculate coax impedance and twisted pair impedance. To calculate coax impedance, it needs inner conductor diameter, inner diameter of surface shield, and substrate electric values. Now, to calculate twisted pair impedance, it needs the diameter of the wires, separation between wires, and substrate dielectric values. Users can also adjust the SI units of input parameters. After the calculation, it not only shows the impedance value, but also provides wire capacitance, delay, and inductance values. It also highlights formulas to calculate impedance, delay, inductance, and capacitance values.

How to calculate transmission line impedance online using eeweb.com:

Go to this website and access the Impedance Calculator.
After that, choose either the Coax Impedance or Twisted Pair Impedance option.
Now, enter the required input values and specify their SI units.
Finally, view the calculated impedance, capacitance, inductance, etc., values.

Additional Features:

This website has multiple online tools like Stripline Calculator, Microstrip Calculator, L-Match Circuit Solvers, Pi-Match Circuit Solvers, Wire Stripline Calculator, and more.

Final Thoughts:

It is another good online wire impedance calculator that can calculate both coax and twisted pair impedance values.

Pros	Cons
Can calculate Coax and twisted pair impedance values
Shows calculation formula
Can also calculate inductance, capacitance, and delay values

Home Page

newark.com

newark.com is yet another free online impedance calculator website. Through this website, users can calculate the impedance of twisted pair cables. Apart from impedance, it can also calculate delay, inductance per inch, and capacitance per inch values. It also shows the formulas to calculate impedance, inductance, delay, and capacitance. A diagram view of twisted pair cables is also present. Now, follow the below steps.

How to calculate impedance online using newark.com:

Go to this website using the provided link.
After that, enter wire diameter, separation between lines, and substrate dielectric values.
Now, hit the Calculate button to view the calculated impedance value in ohms.

Additional Features:

This website offers handy tools like 555 Timer Calculator, LED Series Resistor, . Capacitor Conversion Tool, Battery Life Calculator, etc.

Final Thoughts:

It is another good online impedance calculator website that can calculate impedance and other important parameters of a twisted pair cable.

Pros	Cons
Shows twisted pair cable diagram with annotation
Shows calculation formula
Can calculate inductance, delay, and capacitance values

Home Page

emclab.cei

emclab.cei is the next free online impedance calculator website. This website offers a simple open wire line impedance calculator tool. This tool helps users calculate the impedance of single wire above ground and balanced two-wire lines. To perform the calculation, it needs Dielectric Constant, Height, and Wire Diameter values. It also shows the wire diagrams and shows the calculation process. Now, follow the below steps.

How to calculate impedance online using emclab.cei:

Visit this website using the given link.
After that, choose Single Wire above ground or Balanced two-wire line option.
Next, enter the Dielectric Constant, Wire height, and Wire Diameter values.
Finally, hit the Z0 button to view the wire impedance value.

Final Thoughts:

It is another simple online impedance calculator that can calculate the impedance of both single and two-wire lines.

Pros	Cons
Can calculate the impedance of both single and two-wire lines.
Shows calculation process

Home Page

everythingrf.com

everythingrf.com is another free online impedance calculator website. Through this website, users can find out the impedance, capacitance, inductance, and cut off frequency of a coaxial cable. It also shows all the formulas that it uses to perform the calculation. A coaxial cable diagram with markings are also available. Now, check out the below steps.

How to calculate coaxial cable impedance online using everythingrf.com:

Go to this website and access the Coaxial Cable Impedance calculator.
After that, enter all the required input values.
Next, click on the Calculate button to view the Impedance vale in ohms unit.

Additional Features:

This website offers multiple rf calculators like EIRP, Radar Range, Target Gain Factor, Radar Blind Speed, etc.

Final Thoughts:

It is another simple-to-use online coaxial cable calculator website that offers all the tools calculate impedance of a coaxial cable.

Pros	Cons
Can also calculate inductance and capacitance values	Only calculate impedance of a coaxial cable
Shows calculation formulas

Home Page

Frequently Asked Questions

What is the impedance of electrical wire?

The impedance of an electrical wire depends on various factors, including its dimensions, material properties, and frequency of the electrical signals transmitted through it. For a simple electrical wire used in low-frequency applications, the impedance is primarily determined by its resistance.

What are the 3 types of impedance?

Impedance in electrical circuits is generally classified into three main types namely Resistance, Inductive Reactance, and Capacitive Reactance.

What is the SI unit for impedance?

The SI (International System of Units) unit for impedance is the ohm (symbol: Ω). Impedance, denoted by the symbol Z, is measured in ohms and is used to quantify the opposition that a circuit presents to the flow of alternating current (AC). The ohm is the same unit used to measure resistance (R), which is the opposition to the flow of direct current (DC).

Is impedance for AC or DC?

Impedance is a concept primarily associated with alternating current (AC) circuits. In AC circuits, the impedance (Z) represents the total opposition that a circuit offers to the flow of alternating current, taking into account both resistive and reactive components.

Why do we calculate impedance?

Impedance is a fundamental parameter in the analysis of AC circuits. Unlike DC circuits, where resistance is the primary factor, AC circuits involve impedance, which accounts for both resistive and reactive components. Analyzing impedance helps engineers understand how circuits behave with varying frequencies. In AC power transmission and distribution systems, impedance matching is crucial for efficient power transfer. By calculating and managing the impedance of transmission lines and transformers, engineers can minimize power losses and optimize energy transfer.

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