Resistor in Parallel Calculator by DigiKey

Parallel Resistance Formula:

\[ \frac{1}{R_{total}} = \sum \frac{1}{R} \]

Total Resistance (ohms):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is a Parallel Resistor Calculator?

Definition: This calculator determines the equivalent resistance of resistors connected in parallel.

Purpose: It helps electronics engineers, technicians, and hobbyists design circuits with parallel resistor configurations.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + \cdots \]

Where:

\( R_{total} \) — Equivalent parallel resistance (ohms)
\( R_1, R_2, R_3 \) — Individual resistor values (ohms)

Explanation: The reciprocal of the total resistance equals the sum of reciprocals of individual resistances.

3. Importance of Parallel Resistance Calculation

Details: Proper parallel resistance calculation ensures correct current division, voltage drops, and power distribution in electronic circuits.

4. Using the Calculator

Tips: Enter at least two resistor values (all must be > 0). The third resistor is optional. Results are displayed in ohms.

5. Frequently Asked Questions (FAQ)

Q1: What's special about parallel resistors?
A: In parallel, the total resistance is always less than the smallest individual resistor.

Q2: What if I have more than three resistors?
A: You can chain calculations or modify the code to accept more inputs.

Q3: What happens if one resistor is 0 ohms?
A: The total resistance becomes 0 ohms (short circuit). Our calculator prevents 0 values.

Q4: How does parallel resistance affect current?
A: Current divides among parallel branches inversely proportional to their resistances.

Q5: What's the difference between series and parallel?
A: Series resistors add directly (R_total = R1 + R2), while parallel resistors add reciprocally.