Calculate The Total Resistance of The Following Resistor in Series

When resistors are connected in series, their resistances add up. This calculator helps you find the total resistance of resistors in series, with a simple formula and practical examples.

How to Calculate Series Resistance

Resistors in series create a single path for current flow. The total resistance is simply the sum of all individual resistances. This principle is fundamental in circuit design and troubleshooting.

Remember: Series resistors must be connected end-to-end with no branches. Parallel resistors have a different calculation.

Steps to Calculate

Identify all resistor values in ohms (Ω)
Add them together using the formula below
Verify your calculation with the interactive tool

The Formula

Total Resistance (R_total) = R₁ + R₂ + R₃ + ... + R_n

Where each R represents a resistor's value in ohms. The units remain ohms (Ω) for the total resistance.

Worked Example

Let's calculate the total resistance of three resistors: 10Ω, 20Ω, and 30Ω connected in series.

R_total = 10Ω + 20Ω + 30Ω = 60Ω

The total resistance is 60 ohms. This means the circuit would behave as if it had a single 60Ω resistor.

FAQ

What happens if resistors are in parallel?: The formula changes to 1/R_total = 1/R₁ + 1/R₂ + ... + 1/R_n. This creates a lower total resistance than any single resistor.
Can I use this calculator for AC circuits?: Yes, but be aware that AC circuits may have additional factors like reactance and phase angle that aren't accounted for in this simple DC calculation.
What if I have resistors with different units?: Convert all values to ohms first. For example, 1 kilohm (kΩ) equals 1000 ohms.
How accurate is this calculation?: The formula is exact for ideal resistors. Real-world resistors may have slight tolerances, but this calculation provides a good approximation.