Kirchhoff’s Laws

What Does Kirchhoff’s Laws Mean?

Kirchhoff’s Laws, or circuit laws, are two mathematical equality equations that deal with electricity, current and voltage (potential difference) in the lumped element model of electrical circuits.


Described in 1845 by Gustav Kirchhoff, a German physicist, these laws are considered corollaries of the Maxwell equations for the low-frequency limit for alternating current (AC) circuits. The equations are perfectly accurate for direct current (DC) circuits.

Kirchhoff’s Laws are also known as Kirchhoff’s Voltage Law and Kirchhoff’s Laws For Current And Voltage.

Techopedia Explains Kirchhoff’s Laws

Kirchhoff’s laws are fundamental laws used in electrical engineering and related fields, as well as in formulating proper circuits.

There are two laws, as follows:

  1. Kirchhoff’s Current Law (KCL): This is also known as the first law, point rule or junction rule and is the principle of conservation of electric charge. It states that the amount of current flowing into a node or junction is equal to the sum of the currents flowing out of it. This is used in conjunction with Ohm’s law in performing nodal analysis.

  2. Kirchhoff’s Voltage Law (KVL): This is also known as the second law, loop rule or mesh rule and is based on the principle of conservation of energy. It states that the sum of the voltages or electrical potential differences in a closed network is zero. The total amount of energy gained must equal the amount of energy lost per unit charge.


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Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.