Series Resistor Calculator

Build a circuit, calculate total resistance, and visualize voltage drops automatically.

Circuit Setup
Power Source 12 V
Resistors (Series)
Total Resistance (Rₜ)
0 Ω
Current Flow (I)
0 A

Kirchhoff's Law: Notice how the voltage drops across the resistors in the diagram perfectly add up to your starting power source!

How Series Circuits Work

A "series" circuit means the electrical components are connected end-to-end in a single line. The electricity has only one path to flow through.

  • Total Resistance Adds Up: Because the electrons are forced to push through every single resistor one after another, the total resistance is simply the sum of all individual resistors.
    R_total = R1 + R2 + R3 + ...
  • Current Stays the Same: Think of it like water flowing through a single pipe. The rate of flow (Current / Amps) is exactly the same at every point in the circuit.
    I = Voltage / R_total
  • Voltage Drops: As current forces its way through each resistor, it uses up some of its electrical pressure (Voltage). The amount of voltage lost across a specific resistor is called a "Voltage Drop" and can be calculated using Ohm's Law: V_drop = I × R_individual.