This resistor calculator estimates the total resistance of either parallel or in series resistors or for a conductor. You can discover more about this concern and check the formulas used below the form.


Before pressing "Calculate" button, please input all the resistance values in parallel separated by semicolon (;)
Before pressing "Calculate" button, please input all the resistance values in series separated by semicolon (;)
Conductivity: *
Length: *
Diameter: *

How does this resistor calculator work?

This is an electricity tool that determines the total resistance of a group of resistors, either parallel resistors or in series resistors. The resistor calculator can determine as well the resistance of a conductor. It comprises of three tabs:

  • The first tab calculates the resistance of a group of resistors in parallel circuit,
  • The second tab is designated to calculate the resistance of a group of resistors in series circuit
  • The third tab estimates the resistance of a conductor.

All you have to do is choose the right tab and input the required values.

Parallel circuit

This is the electric circuit in which the components of the circuit are connected between two points. One of the two ends of each component is connected to each point. The components can either be simple elements of branches that have elements in series.

The formula for the total resistance of a group of parallel resistors is:

Rtotal = 1/(1/P1 + 1/P2 + 1/P3 ... + 1/Pn)

where Rtotal is the total resistance and P is the parallel resistors resistance.

Series circuit

This is the electric circuit in which the current goes through every component in that circuit, because the components are placed one following the other. The formula for the total resistance of a group of series resistors is equal to the sum of the resistor’s individual resistances:

Rtotal = P1 + P2 + P3 ... + Pn   

where Rtotal is the total resistance and P is the series resistors resistance.

The resistance of a conductor

This is defined as the opposition encountered by the electrical current in its flow through a conductor. Amongst the factors that influence the resistance there is the thickness or the cross sectional area of the wire, the length of the wire and the temperature. Of course the material of the conductor can also have some degree of determination in the resistance. Conductivity is inversely proportional to resistivity. Therefore the first three factors are the ones to be taken in consideration in the formula below.

- The conductivity of the material (c);

- The length of the conductor (l);

- The diameter of the conductor (d).

The formula is: R=l/(d*c).

27 Mar, 2015 | 0 comments

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