How is parallel inductance calculated?

For uncoupled inductors: 1/L_total = 1/L1 + 1/L2 + … + 1/Ln, so L_total = 1 / (1/L1 + 1/L2 + …). This always yields a value smaller than the smallest individual inductor.

What does the coupling coefficient k do?

When two inductors share a magnetic core or are physically close, their mutual inductance M = k × √(L1 × L2) affects the combined value. For aiding flux (series-aiding orientation), the parallel equivalent shifts accordingly. This calculator applies the mutual coupling correction for exactly two inductors.

Why is parallel inductance always less than any single inductor?

Adding a parallel path gives magnetic flux an additional route, effectively reducing the total opposition to current change (inductance). The reciprocal formula guarantees L_total < min(L1, L2, …).

What units are supported?

Each inductor can be entered in henries (H), millihenries (mH), microhenries (µH), or nanohenries (nH). The calculator converts everything to henries before computing.

When should I use the mutual coupling option?

Use it only when two inductors share a core or are wound on the same bobbin. For inductors on separate cores or with adequate spacing, k ≈ 0 and the standard reciprocal formula applies.

Inductors in Parallel Calculator

Name: Inductors in Parallel Calculator
Availability: InStock
Author: Nham Vu

Enter 2–8 inductor values to calculate their total parallel inductance, with an optional mutual coupling correction for two coupled coils.

Inductor Values

Mutual Coupling (2 inductors only)

Add exactly 2 inductors to enable this option.

Total Parallel Inductance

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Formula

1/L_total = 1/L₁ + 1/L₂ + …

Individual Values

Summary

Enter 2–8 inductor values to calculate their total parallel inductance, with an optional mutual coupling correction for two coupled coils.

How it works

Enter the value for each inductor and choose its unit (H, mH, µH, or nH).
Click "Add Inductor" to add more inductors — up to 8 total.
The calculator converts all values to henries and applies the reciprocal formula: 1/L_total = 1/L1 + 1/L2 + …
For exactly two inductors, enable "Mutual Coupling" and enter the coupling coefficient k (0–1) to include a mutual inductance correction.
The total inductance is displayed alongside the reciprocal formula with your values substituted.

Use cases

Design LC filter circuits that need a specific lower inductance than any individual coil.
Combine off-the-shelf inductors to hit a precise target value.
Model magnetically coupled transformer windings using the coupling coefficient.
Verify parallel inductor configurations in RF and power electronics schematics.
Teach or learn the parallel inductance reciprocal rule.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu