Inductance Converter
Convert between inductance units — henry, kilohenry, millihenry, microhenry, nanohenry, picohenry, femtohenry, abhenry, stathenry, and weber/ampere.
Results from this calculator are estimates provided for general informational purposes only, based on formulas, rates, and standards commonly accepted as of 2026. Figures may differ slightly from other calculators or professional sources due to rounding methods, differing assumptions, or regional regulations, and rules may change over time. Always consult a qualified professional — such as a financial advisor, healthcare provider, or other relevant specialist — before making decisions based on these results.
Result
1 H = 1000 mH
1 Henry = 1000 Millihenries
1 Millihenry = 0.001 Henries
1 H in every supported unit
What is an Inductance Converter?
Inductance is the property of an electrical conductor that opposes a change in the current flowing through it, by generating an opposing electromotive force as the current rises or falls. Its SI derived unit is the henry (H), defined as the inductance of a circuit in which one volt is produced when the current through it changes at a rate of one ampere per second. Inductors — coils of wire, often wound around a magnetic core — are rated in henries, but a full henry is a large amount of inductance for a small physical coil, so almost every real inductor you'll encounter is rated in millihenries or microhenries, while parasitic wiring and chip-package inductance is often small enough to need nanohenries or picohenries.
This converter is used whenever an engineer, technician, or student needs to move between those scales — reading an inductor's printed millihenry or microhenry value, converting an older physics text's abhenry or stathenry figure (from the 19th-century CGS unit systems) into modern henries, or working through a flux-linkage calculation expressed in the base weber/ampere relationship. Every unit below is defined relative to the henry, so any two inductance units — modern SI or historical CGS — convert directly and consistently.
Conversion chart: Henry to Millihenries
Conversion table
| Henry (H) | Millihenry (mH) |
|---|---|
| 0.01 H | 10 mH |
| 0.1 H | 100 mH |
| 1 H | 1000 mH |
| 2 H | 2000 mH |
| 3 H | 3000 mH |
| 5 H | 5000 mH |
| 10 H | 10000 mH |
| 20 H | 20000 mH |
| 50 H | 50000 mH |
| 100 H | 100000 mH |
| 1000 H | 1000000 mH |
Supported Units
| Unit | Symbol | In Henry |
|---|---|---|
| Henry | H | 1 H |
| Kilohenry | kH | 1000 H |
| Millihenry | mH | 0.001 H |
| Microhenry | µH | 1E-06 H |
| Nanohenry | nH | 1E-09 H |
| Picohenry | pH | 1E-12 H |
| Femtohenry | fH | 1E-15 H |
| Abhenry | abH | 1E-09 H |
| Stathenry | statH | 8.98755E+11 H |
| Weber/Ampere | Wb/A | 1 H |
About These Parameters
- Value
- The inductance value you want to convert, expressed in the "From" unit. Accepts decimals, and can represent anything from a tiny nanohenry PCB-trace parasitic to a large power-transformer winding's multi-henry rating.
- From Unit
- The unit your input value is currently measured in — an inductor datasheet's millihenry or microhenry rating, or a historical figure quoted in abhenries or stathenries from the older CGS unit systems.
- To Unit
- The unit you want the result converted into. Use the swap button to flip From and To instantly, handy when translating a datasheet value into a different SI-prefixed scale or back to the base henry.
How Inductance Conversion Works
The Formula
Every unit here is defined by a fixed multiplier relative to the henry. To convert a value from one unit to another:
result = value × (factor of "From" unit ÷ factor of "To" unit)
For Henry → Millihenry: multiply by 1000. For example, 1 H × 1000 = 1000 mH.
Why Inductors Span Such a Wide Range of Units
A henry is a relatively large amount of inductance for a physical coil to produce — winding enough turns around a large enough core to reach a full henry generally means a bulky component, the kind found in mains-frequency power transformers and large chokes. Most inductors used in switching power supplies, RF circuits, and signal filtering only need a fraction of a henry to do their job, which is why millihenries and microhenries are the everyday scale for real components. At the other extreme, any wire, PCB trace, or connector lead has some small amount of unavoidable "parasitic" inductance — usually measured in nanohenries or picohenries — that becomes significant only at the high frequencies and fast switching speeds used in modern digital and RF electronics.
SI Henries vs. CGS Abhenries and Stathenries
Before the SI system unified electrical units around the henry, volt, and ampere, 19th-century physicists worked in the centimeter-gram-second (CGS) system, which split into two competing branches: the electromagnetic (emu) branch, whose inductance unit is the abhenry (equal to a tiny one billionth of a henry), and the electrostatic (esu) branch, whose unit is the stathenry (equal to a massive 898.8 billion henries). That enormous gap — the mirror image of the abfarad/statfarad relationship in capacitance — comes from the same speed-of-light-squared relationship that links the esu and emu systems throughout classical electromagnetism. Modern electronics almost never uses either CGS unit directly, but they still turn up when translating older theoretical physics texts into today's henry-based units.
Example
An inductance of 1 H equals 1000 mH. For scale, a small RF inductor on a circuit board might be rated around 10 microhenries, a typical switching power-supply inductor might be a few hundred microhenries to a few millihenries, and a large mains-frequency power transformer winding can reach several henries.
Frequently Asked Questions
Why are inductors almost never rated in whole henries?
A henry is a relatively large amount of inductance to build into a small, practical coil — reaching a full henry typically requires a bulky winding around a large magnetic core, the kind used in mains-frequency transformers. Everyday inductors in power supplies, RF circuits, and filters only need a fraction of a henry, so they're rated in millihenries or microhenries instead.
Is weber/ampere the same thing as a henry?
Yes — they're mathematically identical. The henry is defined as exactly one weber of magnetic flux linkage per ampere of current (1 H = 1 Wb/A), so expressing an inductance in webers per ampere gives the exact same numeric value as expressing it in henries.
Why is the stathenry so much larger than the abhenry?
Both come from the older centimeter-gram-second (CGS) system, but from opposite branches: the abhenry is a CGS electromagnetic (emu) unit, while the stathenry is a CGS electrostatic (esu) unit. The two branches are related by the speed of light squared, which is why the abhenry (10⁻⁹ henries) and stathenry (about 8.9876 × 10¹¹ henries) sit roughly 21 orders of magnitude apart despite both measuring inductance.
What's a typical inductance value for common electronics?
It depends heavily on the application: RF and high-frequency tuning circuits often use nanohenry to microhenry inductors, switching power-supply inductors commonly range from a few microhenries to a few millihenries, and large mains-frequency transformer or motor windings can reach several henries. Kilohenry-scale inductance is essentially never seen outside specialized grid equipment.