Loading Calculator...
Please wait a moment
Please wait a moment
Convert between all inductance units: henrys, millihenrys, microhenrys, and nanohenrys. Perfect for inductor selection and filter design.
Inductance is the property of an electrical conductor that opposes changes in current flow. Measured in henrys (H), it quantifies how much voltage is induced when current changes. Inductors store energy in magnetic fields and are essential in power supplies, filters, transformers, and RF circuits. Named after Joseph Henry, the henry is a relatively large unit, so most practical inductors are rated in millihenrys or microhenrys.
Choose the unit that gives the most convenient numerical values. Use nH for very small inductors (chip inductors, PCB traces), µH for small to medium inductors (power supply inductors, RF coils), mH for larger inductors (audio chokes, power line filters), and H for transformers and very large inductors.
Inductance depends on the number of wire turns, core material (air, ferrite, iron powder), core geometry, and physical dimensions. Adding a ferromagnetic core increases inductance dramatically compared to air-core designs. Current level can reduce inductance in cores approaching saturation. Temperature and frequency also affect measured values.
Basic multimeters cannot measure inductance. You need an LCR meter or dedicated inductance meter. These instruments apply an AC signal at a specific frequency and measure the resulting impedance to calculate inductance. The measurement frequency matters because inductance can vary with frequency, especially in cores with losses.
Inductance (measured in henrys) is an intrinsic property of the component. Inductive reactance (XL = 2πfL) is the AC impedance contributed by inductance, measured in ohms and varying with frequency. Total impedance includes both resistance and reactance. At DC (0 Hz), an ideal inductor has zero reactance but real inductors have some DC resistance.
Simple inductors don't have polarity and can be connected either way. However, transformers and coupled inductors have phase relationships indicated by dots on schematics. Some power inductors have directional cores optimized for DC bias. Always check datasheets for components with multiple windings or special construction.