This calculator determines the total effective resistance of any number of resistors in series and parallel configurations.

**Series Resistance **Calculator

Enter the resistor values separated by commas.

**Series Resistance Formula**

**R _{total} = R_{1} + R_{2} + R_{3 }+…. + R_{n}**

**Example Calculation**

Consider four resistors in parallel: 1 Ω, 6 Ω, 15 Ω and 100 Ω. The total effective resistance is 122 Ω.

If you have two resistors – one large and the other small in parallel, the effective resistance is closer to the larger value. Take for instance 1 Ω and 1000 Ω in series. The effective resistance is 1001 ≈ 1000 Ω.

**Parallel Resistance **Calculator

Enter the resistor values separated by commas.

**Parallel Resistance Formula**

**R _{total} = (1/R_{1} + 1/R_{2} + 1/R_{3 }+…. + 1/R_{n})^{-1}**

**Example Calculation**

Consider four resistors in parallel: 1 Ω, 6 Ω, 15 Ω and 100 Ω. The total effective resistance is 0.80 Ω.

If you have two resistors – one large and the other small in parallel, the effective resistance is closer to the smaller value. Take for instance 1 Ω and 100 Ω in parallel. The effective resistance is 0.99 ≈ 1 Ω.

## Series and **Parallel Resistance **Calculator

Enter the series and parallel resistor values in two separate fields separated by commas.

## Series and **Parallel Resistance Formula**

**R _{parallel} = (1/R_{1} + 1/R_{2} + 1/R_{3 }+…. + 1/R_{n})^{-1}**

**R _{series} = R_{1} + R_{2} + R_{3 }+…. + R_{n}**

**R _{total}** =

**R**

_{parallel}+ R_{series}**Example Calculation**

Consider three resistors in parallel: 1 Ω, 3 Ω, and 5 Ω and two resistors in series 1 Ω and 2 Ω

The total parallel resistance **R _{parallel} = 0.652 Ω**

The total series resistance **R _{series}**

**=**

**3 Ω**

The total effective resistance **R _{total}** =

**3.652 Ω**