Parallel Resistance Calculator

Equivalent Resistance of Parallel Resistors

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Resistance values

Rₙ

Enter resistance values separated by commas (Ω)

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Equivalent Resistance

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Parallel Resistor Formula

$$R_{\text{total}} = \frac{R_1 \cdot R_2}{R_1 + R_2}$$ $$\frac{1}{R_{\text{total}}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + \ldots + \frac{1}{R_n}$$

Where:

• $$R_{ ext{total}}$$ = total equivalent resistance (Ω)
• $$R_1$$, $$R_2$$, $$\ldots$$, $$R_n$$ = individual resistances (Ω)

This rule reduces total resistance and increases the current-carrying capacity.

Parallel Resistance – Calculation Example

Given:

• $$R_1$$ = 100 Ω
• $$R_2$$ = 200 Ω
• $$R_3$$ = 300 Ω

Calculation:

1. $$\frac{1}{R_{\text{total}}} = \frac{1}{100} + \frac{1}{200} + \frac{1}{300} = 0.01 + 0.005 + 0.00333 ≈ 0.01833$$
2. $$R_{\text{total}} ≈ \frac{1}{0.01833} ≈ 54.55~Ω$$

Parallel resistor networks are common in electronics when precise values are needed or when distributing power across multiple components. This calculator helps quickly determine the total resistance of any number of resistors connected in parallel. It is ideal for use in low-resistance applications, power supplies, voltage dividers, and current-sharing designs.