How to use the inductance converter
- Enter the inductance in Value.
- Choose its unit in From: henries, millihenries, microhenries, nanohenries, abhenries or stathenries.
- Choose the unit you want in To and read the result.
- The table shows all six units at once. Press the swap button to go the other way.
What it does and when to use it
Inductors show up at very different scales. Mains chokes and loudspeaker crossover coils are in millihenries. Power inductors in switch-mode supplies are typically in microhenries. RF coils, ferrite beads and the stray inductance of a PCB trace or a component lead are in nanohenries. Simulators, datasheets and parts shops do not always use the same prefix, so a quick conversion avoids ordering a part a thousand times too large or small.
When you design a filter or resonant circuit, the capacitance converter handles the other half of the LC pair. The resonant frequency is f = 1 ÷ (2π√(LC)) with L in henries and C in farads, so convert both to base units first. The frequency ↔ wavelength converter then turns that frequency into a wavelength. For the magnetic side of a coil, the magnetic flux converter covers webers and maxwells.
How it works
Every unit has a factor in henries. The result is value × from-factor ÷ to-factor:
| Unit | Henries |
|---|---|
| millihenry | 0.001 |
| microhenry | 0.000001 |
| nanohenry | 0.000000001 |
| abhenry | 0.000000001 |
| stathenry | c² × 10⁻⁵ ≈ 898,755,178,737 |
The stathenry uses the exact speed of light, c = 299,792,458 m/s. The rest are SI prefixes, which are exact powers of ten.
Worked examples
Buck converter inductor. 470 µH = 0.47 millihenries.
RF coil. A 15 nH chip inductor is 0.015 microhenries, or 0.000000015 H in the table.
CGS check. 1 abhenry = 1 nanohenry. The two rows in the table are always equal.
Limits and tips
- The value printed on an inductor is usually measured at one test frequency and with no DC current. Under load, many power inductors lose inductance as the core nears saturation.
- Tolerance is not part of a unit conversion. Read it from the datasheet, along with the saturation and rated currents.
- Results smaller than 1e-9 of the target unit appear in scientific notation, such as 1.11265e-21 stathenries for 1 nH.
Frequently asked questions
How many microhenries are in a millihenry?
What does 101 or 4R7 printed on an inductor mean?
Why does an abhenry give the same number as a nanohenry?
What is a stathenry?
Can I calculate the inductance of a coil here?
Sources
- NIST Guide to the SI, Appendix B.8: Factors for units listed alphabetically — NIST, accessed 2026-10-08
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