Series Resistance Calculator Formula
Understand the math behind the series resistance calculator. Each variable explained with a worked example.
Formulas Used
Total Resistance
total_resistance = r1 + r2 + r3Variables
| Variable | Description | Default |
|---|---|---|
r1 | Resistor 1(Ω) | 100 |
r2 | Resistor 2(Ω) | 220 |
r3 | Resistor 3 (0 if unused)(Ω) | 330 |
How It Works
Series Resistance
Resistors in series carry the same current, and their resistances add directly.
Formula
R_total = R1 + R2 + R3 + ...
The total resistance is always greater than the largest individual resistor.
Worked Example
Three resistors in series: 100, 220, and 330 ohms.
- 01R_total = R1 + R2 + R3
- 02R_total = 100 + 220 + 330
- 03R_total = 650 Ω
Frequently Asked Questions
What happens to current in a series circuit?
Current is the same through every component. The total voltage divides across the resistors proportional to their resistance.
Why would you connect resistors in series?
To create a larger resistance value or to build a voltage divider circuit.
What if one resistor in a series circuit fails open?
The entire circuit breaks and no current flows, like a burnt-out bulb on old Christmas lights.
Learn More
Guide
How to Calculate Series and Parallel Circuits
Learn how to analyze series and parallel resistor, capacitor, and inductor circuits. Includes formulas for total resistance, voltage, and current with worked examples.
Ready to run the numbers?
Open Series Resistance Calculator