# How to Calculate Kirchhoff's Current Law (KCL)

A short tutorial on Kirchhoff's current law(KCL) to determine the current in the electric circuit with the simple example.

## Electric Circuit Analysis

Current Kirchhoffs Law or Kirchhoffs Current Law is also referred as **Kirchhoffs first law**, **Kirchhoffs point rule**, or **Kirchhoffs junction rule**. KCL explains about the conversation of charge entering and leaving a junction. To put it in detail, it states that "the charge entering the node is exactly equal to the current leaving the node as its only option is to leave the node, as no charge can be lost within the node. The sum of current entering and leaving a junction is equal to Zero. The first law of Kirchhoffs is also known as **Conservation of Charge**. Learn here how to calculate Kirchhoffs current law (KCL).

In an electric circuit analysis, the current in the circuit can be expressed as follows.

**Kirchhoffs Current Law Formula:**

I_{(exiting)} + I_{(entering)} = 0

The above image is an example of Kirchhoffs first law. Two positive currents I_{1},I_{2},_{ }are entering the node three positive currents are leaving the node, I_{3}, I_{4} and I_{5}.

Kirchhoffs Current L**aw Example: **

Step 1: Lets consider a simple single junction as an example. The amps of the current I_{1},I_{2 }entering the node is 6 amps and 5 amps respectively. The amps of the current I_{3}, I_{4} and I_{5} leaving the node is 4 amps, 5 amps and 2 amps.

I_{1} - 6 amps

I_{2 }- 5 amps

I_{3} - 4 amps

I_{4 }- 5 amps

I_{5 }- 2 amps

**Step 2: Here we have the formula**

I_{1} + I_{2} = I_{3} + I_{4} + I_{5}Substituting the values in the formula.

6 + 5 = 4 + 5 + 2

11 = 11 amps

Here as per Kirchhoff law, the total current entering the node is equal to the total current leaving the node. The example holds true for the Kirchhoffs current law.

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