Inductors in series behave like resistors in series: their inductances simply add, provided their magnetic fields don’t couple. Designers combine standard values this way to hit an exact inductance.
How to use the Series Inductors Calculator
- Calculate
- Target total inductance
- Inductor 1
- Inductor 2
- Inductor 3
- Inductor 4
- Inductor 5
- Inductor 6
- Inductor 7
- Inductor 8
- Inductor 9
- Inductor 10
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Choose the mode and enter the inductances (leave unused fields at 0).
Inputs explained
| Field | What to enter |
|---|---|
| Calculate | Choose one: Total inductance, Missing inductor |
| Target total inductance | Units: mH, µH, nH, H |
| Inductor 1 | Units: mH, µH, nH, H |
| Inductor 2 | Units: mH, µH, nH, H |
| Inductor 3 | Units: mH, µH, nH, H |
| Inductor 4 | Units: mH, µH, nH, H |
| Inductor 5 | Units: mH, µH, nH, H |
| Inductor 6 | Units: mH, µH, nH, H |
| Inductor 7 | Units: mH, µH, nH, H |
| Inductor 8 | Units: mH, µH, nH, H |
| Inductor 9 | Units: mH, µH, nH, H |
| Inductor 10 | Units: mH, µH, nH, H |
What each result means
- Total inductance = [Inductor 1] + [Inductor 2] + [Inductor 3] + [Inductor 4] + [Inductor 5] + [Inductor 6] + [Inductor 7] + [Inductor 8] + [Inductor 9] + [Inductor 10]
- Missing inductor = [Target total inductance] – ([Inductor 1] + [Inductor 2] + [Inductor 3] + [Inductor 4] + [Inductor 5] + [Inductor 6] + [Inductor 7] + [Inductor 8] + [Inductor 9] + [Inductor 10])
Example values
How the main result changes when Target total inductance changes and everything else stays at the example values above:
| Target total inductance (mH) | Total inductance (mH) |
|---|---|
| 50 | 79 |
| 75 | 79 |
| 100 | 79 |
| 125 | 79 |
| 150 | 79 |
| 200 | 79 |
Formula
L_total = L₁ + L₂ + … + L_n · Missing: L_x = L_target − ΣL_i
Worked example
Inputs — Calculate: Total inductance; Inductor 1: 10 mH; Inductor 2: 22 mH; Inductor 3: 47 mH; Inductor 4: 0 mH; Inductor 5: 0 mH; Inductor 6: 0 mH; Inductor 7: 0 mH; Inductor 8: 0 mH; Inductor 9: 0 mH; Inductor 10: 0 mH.
Results — Total inductance = 79 mH.
Key terms
- Mutual inductance
- Coupling between two coils' magnetic fields.
Frequently asked questions
Do series inductances always add?
Only without mutual coupling; coupled coils add ±2M.
How do I avoid coupling?
Space the inductors apart or mount them at right angles.
Is it like resistors?
Yes – series inductors add like series resistors.
What happens to current rating?
The same current flows through each, so the lowest rating limits it.