Convert inductance between henries, millihenries, microhenries and nanohenries.
Electricity • 6 units
All 6 units on the Inductance Converter are defined against the Henry (H), so each result is one conversion factor away from a single reference rather than the end of a chain of roundings.
The conversion this page is most often opened for is ready before you type anything: 1 mH = 1,000 µH. Change either side and every row in the table recalculates with it.
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Millihenries to microhenries is a plain factor of a thousand, but the number that decides whether an inductor is doing its job is reactance rather than inductance. Reactance rises with frequency as 2πfL, so a 10 µH choke presents about 63 Ω at 1 MHz and only 0.63 Ω at 10 kHz. The same component is a barrier at one frequency and nearly a short circuit at another, which is why filter parts cannot be selected on henries alone.
The table hides one genuinely convenient coincidence: the abhenry is exactly 10⁻⁹ H, so an abhenry and a nanohenry are the same quantity and older CGS magnetics tables can be read directly in nanohenries with no arithmetic. The stathenry at the other end is about 8.99 × 10¹¹ H, a figure no physical component approaches, and it exists only for electrostatic-unit treatments. Where a value from an old text looks plausible, it is far more likely to be in abhenries than stathenries.
An inductor's henries are also conditional on the current flowing through it. Ferrite and powdered-iron cores saturate, and once the core saturates the inductance collapses — which is why datasheets quote a saturation current, usually defined as the point where inductance has fallen by 20% or 30% from its small-signal value. A converter changes the units of the marked figure; it cannot tell you that the part is being run past the knee, where the stored energy ½LI² stops rising and the current waveform turns sharply upward.
Quick reference — 1 Millihenry (mH) is equal to:
| Henry | H | 0.001 |
| Microhenry | µH | 1,000 |
| Nanohenry | nH | 1,000,000 |
| Abhenry | abH | 1,000,000 |
| Stathenry | statH | 1.112650e-15 |
6 units of inductance, each a fixed multiple of the H. The table spans 898,755,200,000,000,000,000:1, from nH (0.000000001 H) to statH (898755000000 H). Conversion is one multiplication into the base unit and one division out of it, with no lookup table and no approximation.
value_to = value_from × (factor_from ÷ factor_to)1 H = 1 H1 mH = 0.001 H1 µH = 0.000001 H1 nH = 0.000000001 H1 abH = 0.000000001 H1 statH = 898755000000 Hwhere:
Assumptions: Factors are exact definitions. Full double precision is carried internally and rounding is applied only for display.
Result25 mH = 25000 µH
Inductance measures how strongly a conductor opposes a change in current by storing energy in a magnetic field. The henry (H) is defined so that a current changing at one ampere per second induces one volt across a one-henry inductor.
Like the farad, the henry is a large unit in practice. Power-supply chokes are typically measured in millihenries, radio-frequency coils in microhenries, and the parasitic inductance of a short length of circuit-board track in nanohenries. That last figure is the one that catches people out: a few nH of lead inductance is irrelevant at mains frequency and completely dominant at hundreds of megahertz, which is why high-speed decoupling capacitors are placed as physically close to the chip as possible.