The Effective Inductance Calculator helps you determine the total inductance of a group of inductors connected either in series or parallel in an electrical circuit. This tool is commonly used in electronics design and analysis, especially in applications involving filters, oscillators, or transformers.
This calculator falls under the Electronics Calculators category. It simplifies the process of calculating total inductance, allowing engineers, students, and hobbyists to verify circuit performance and ensure component compatibility without doing manual math for each configuration.
By entering the inductance values of the individual inductors, the calculator instantly shows the effective inductance—helping you save time and avoid errors in circuit design.
formula of Effective Inductance Calculator
For Inductors in Series:
L_eff = L1 + L2 + L3 + … + Ln
In a series connection, inductances simply add up because the magnetic fields of the inductors reinforce each other.
For Inductors in Parallel:
1 / L_eff = 1 / L1 + 1 / L2 + 1 / L3 + … + 1 / Ln
In a parallel connection, the inverse of the effective inductance is the sum of the inverses of individual inductances. This configuration reduces the overall inductance, much like how resistors behave in parallel.
Variables:
L_eff:
Effective Inductance — the total inductance in the circuit, usually expressed in Henries (H), milliHenries (mH), or microHenries (µH).
L1, L2, L3, …, Ln:
The inductance values of individual inductors in the circuit, all measured in the same unit as L_eff.
These formulas are critical in designing reliable electronic circuits and ensuring components work together as intended.
Reference Table: Common Inductor Combinations
| Configuration | L1 (mH) | L2 (mH) | Total L_eff (mH) |
|---|---|---|---|
| Series | 3 | 5 | 8 |
| Series | 10 | 15 | 25 |
| Parallel | 4 | 4 | 2 |
| Parallel | 6 | 3 | 2 |
| Parallel | 5 | 10 | 3.33 |
This table offers a quick look at common values so users can estimate results without full calculations.
Example of Effective Inductance Calculator
Problem:
You have two inductors:
L1 = 6 mH and L2 = 3 mH
Case 1: Series Connection
L_eff = L1 + L2
L_eff = 6 + 3 = 9 mH
Case 2: Parallel Connection
1 / L_eff = 1 / L1 + 1 / L2
1 / L_eff = 1 / 6 + 1 / 3 = (1 + 2) / 6 = 3 / 6
L_eff = 6 / 3 = 2 mH
Result:
- In series: total inductance is 9 mH
- In parallel: total inductance is 2 mH
Most Common FAQs
A: Use the series formula when inductors are connected end-to-end in a single path. Use the parallel formula when each inductor is connected directly to the same two points in the circuit.
A: No. Convert all values to the same unit before calculating. For example, convert µH to mH if others are in mH.
A: In a parallel configuration, magnetic fields oppose each other, which reduces the overall ability to store energy—thus lowering the effective inductance.