Series Resistance Calculator: Formula, Working, and Example Calculation

Introduction

Calculating total resistance in series circuits is a must-know skill for electrical engineers and students. Series circuits are widely used in electrical systems where devices are connected one after another, forming a single path for current flow. This guide explains the formula for series resistance, offers example problems, and provides a practical online calculator.

What is a Series Circuit?

A series circuit connects resistors end-to-end so that current flows through each resistor sequentially. When one device is turned off or fails, current stops for the entire circuit. Series circuits are commonly used in simple circuit arrangements, safety devices, and measurement setups.

Series Resistance Formula

The formula for total resistance in a series circuit is straightforward:
R_total = R_1 + R_2 + R_3 + … + R_n
Where:

• R_total = Total resistance of the series circuit
• R_1, R_2, …, R_n = Individual resistor values

Step-by-Step Calculation Example

Suppose you have three resistors in series:

• R_1 = 10Ω
• R_2 = 20Ω
• R_3 = 30Ω

Using the formula:
R_total = 10 + 20 + 30 = 60Ω

Series Resistance Calculator

Key Takeaways

• Series resistance is the sum of all resistor values.
• Series circuits provide only one path for current; a break stops the entire circuit.
• Ideal for safety and measurement applications.