Resistor Calculator

    Calculate equivalent resistance for up to three resistors in series or parallel.

    Inputs

    About Series and Parallel Resistors

    Understanding how resistors combine in series and parallel is fundamental in electrical and electronic circuit design. Series resistors increase total resistance, while parallel resistors decrease it. Real resistors have tolerances and temperature coefficients that affect precise calculations. This calculator helps you determine the total resistance, voltage distribution, and current in circuits for both series and parallel configurations.

    •Features

    • –Calculates total resistance for both series and parallel resistor combinations.
    • –Handles multiple resistors at once with flexible input options.
    • –Accounts for resistor tolerances and temperature coefficients for realistic calculations.
    • –Provides voltage and current distribution insights for series and parallel circuits.
    • –Clear, easy-to-read layout with step-by-step breakdowns of calculations.

    •How to Use

    1. 1.Enter the resistor values in ohms for all resistors in your circuit.
    2. 2.Select whether the resistors are connected in series or parallel.
    3. 3.Click “Calculate” to determine the total resistance of the network.
    4. 4.Optionally, enter supply voltage to view current and voltage distribution across each resistor.
    5. 5.Use these results to design and analyze circuits accurately and efficiently.

    •Key Concepts

    • –Series Resistors: Total resistance is the sum of all resistors: R_total = R1 + R2 + R3 + …
    • –Parallel Resistors: Total resistance is found via: 1/R_total = 1/R1 + 1/R2 + 1/R3 + …
    • –Voltage Division: In series circuits, voltage divides proportionally to resistor values.
    • –Current Distribution: In parallel circuits, current divides inversely proportional to resistance.
    • –Resistor Tolerance: Real resistors vary from nominal value by a tolerance (e.g., ±5%), affecting total resistance.

    •Formulas Used

    • –Series: R_total = R1 + R2 + R3 + …
    • –Parallel: 1/R_total = 1/R1 + 1/R2 + 1/R3 + …
    • –Voltage Divider: Vx = (Rx / R_total) × V_supply
    • –Current in Parallel: Ix = V_supply / Rx

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