Kirchhoff's Voltage Law (KVL) Calculator

Kirchhoff's Voltage Law states that the sum of all voltages around any closed loop in a circuit must equal zero — this calculator applies that principle to a series-parallel resistor circuit. Enter your Source Voltage (Vin) and the values of Resistor R1, Resistor R2, and Resistor R3 (Load) to get the Total Current (I1), branch currents I2 and I3, the voltage drop across each resistor, and a KVL Sum Verification confirming the loop voltages balance to zero.

V

Input voltage source in the circuit

Ω

First resistor value in ohms

Ω

Second resistor value in ohms

Ω

Load resistor value in ohms

Number of decimal places for results

Results

Total Current (I1)

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Current I2

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Current I3

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Voltage across R1

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Voltage across R2

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Voltage across R3

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KVL Sum Verification

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Results Table

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Frequently Asked Questions

What is Kirchhoff's Voltage Law (KVL)?

Kirchhoff's Voltage Law states that the algebraic sum of all voltages around any closed loop in a circuit must equal zero. This fundamental principle is based on the conservation of energy in electrical circuits.

How do you apply KVL to a series circuit?

In a series circuit, start at any point and trace around the loop, adding voltage drops across resistors as negative values and voltage sources as positive values. The sum should equal zero if KVL is satisfied.

What's the difference between KVL and KCL?

KVL (Kirchhoff's Voltage Law) deals with voltages around closed loops and states their sum equals zero. KCL (Kirchhoff's Current Law) deals with currents at nodes and states that current entering a node equals current leaving it.

Why is KVL important in circuit analysis?

KVL is essential for solving complex circuits with multiple loops and components. It provides a systematic method to write equations that can be solved to find unknown voltages and currents throughout the circuit.

Can KVL be applied to AC circuits?

Yes, KVL applies to both DC and AC circuits. In AC circuits, you work with phasor representations of voltages and currents, but the fundamental principle that voltage drops sum to zero around any closed loop remains valid.

What happens if KVL doesn't balance in my calculation?

If KVL doesn't balance (sum doesn't equal zero), it indicates an error in your circuit analysis, such as incorrect sign conventions, missed components, or calculation mistakes. Double-check your work and component values.

How do you handle voltage sources in KVL equations?

Voltage sources are treated as positive when you traverse them from negative to positive terminal, and negative when traversing from positive to negative terminal. This sign convention ensures proper application of KVL.