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Resistors Calculator

Calculate Equivalent Resistance

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Enter resistor values and select circuit type to calculate equivalent resistance

About Series & Parallel Resistors

Calculating the equivalent resistance of resistors in series or parallel is fundamental in circuit analysis. The total resistance depends on how the resistors are connected.

Key Formulas:

  • Series: Req = R₁ + R₂ + ... + Rn
  • Parallel: 1/Req = 1/R₁ + 1/R₂ + ... + 1/Rn

Applications:

  • Voltage dividers
  • Current limiting
  • Load balancing
  • Sensor circuits
  • Power distribution

Tips:

  • Series: Current is the same through all resistors, voltage divides.
  • Parallel: Voltage is the same across all resistors, current divides.
  • For mixed circuits, reduce in steps: solve series and parallel groups iteratively.