Inductance Converter
Convert inductance between henry and every metric prefix from attohenry to exahenry, weber per ampere, and the CGS units abhenry and stathenry. Pick two units, enter a value and read the result instantly. Very small and very large values appear in scientific notation.
Select two units to see the conversion factor.
This tool converts inductance (H) only. It is not capacitance (F), and not magnetic flux (Wb). Note that mH is millihenry but MH is megahenry, and pH is picohenry but PH is petahenry.
Inductance Formula
Every inductance unit is a fixed multiple of the henry. Result = value × (source factor ÷ target factor). The prefixes are exact powers of ten, from 1 aH = 10⁻¹⁸ H up to 1 EH = 10¹⁸ H, so 1 mH = 1,000 µH and 1 µH = 1,000 nH. A weber per ampere is exactly one henry. The CGS units are exact too: 1 abhenry = 10⁻⁹ H, and 1 stathenry = c² × 10⁻⁵ H ≈ 8.98755 × 10¹¹ H, derived from the exact speed of light.
What Is Inductance?
Inductance is the property of a conductor, usually a coil, that opposes a change in the current through it. When the current changes, the changing magnetic flux induces a voltage that pushes back: V = L × dI/dt. Inductance is also the ratio of linked magnetic flux to current, L = Φ ÷ I. The SI unit is the henry (H), the inductance in which a current changing at one ampere per second induces one volt. An inductor stores energy in its magnetic field, E = ½ × L × I².
The henry is a large unit for most electronics. Power-supply chokes and filter inductors are in millihenries (mH), switching-converter and audio-crossover coils in microhenries (µH) and radio-frequency coils, PCB traces and bond wires in nanohenries (nH). Mains transformers and large smoothing chokes can reach henries, and superconducting magnets are measured in tens or hundreds of henries.
Case matters in the symbols: mH is a millihenry (10⁻³ H), MH a megahenry (10⁶ H); pH is a picohenry (10⁻¹² H), PH a petahenry (10¹⁵ H). The weber per ampere is just another name for the henry. The abhenry (the EMU of inductance, 10⁻⁹ H, equal to one nanohenry) and the stathenry (the ESU of inductance, about 9 × 10¹¹ H) are the CGS units; the stathenry is enormous and appears only in Gaussian-unit physics texts.
Do not confuse inductance with related quantities. It is not capacitance, which stores energy in an electric field (Electrostatic Capacitance Converter). It is not magnetic flux, measured in webers (Magnetic Flux Converter), though flux per ampere gives inductance. And it is not resistance (Electric Resistance Converter), which dissipates energy instead of storing it.
Supported Units
This converter supports the following 22 inductance units. The last column gives the value of each unit in the base unit, the henry. The weber per ampere equals the henry, the abhenry equals the EMU of inductance, and the stathenry equals the ESU of inductance.
| Unit | Symbol | Value in H |
|---|---|---|
| Henry | H | 1 |
| Exahenry | EH | 1e+18 |
| Petahenry | PH | 1e+15 |
| Terahenry | TH | 1e+12 |
| Gigahenry | GH | 1,000,000,000 |
| Megahenry | MH | 1,000,000 |
| Kilohenry | kH | 1,000 |
| Hectohenry | hH | 100 |
| Dekahenry | daH | 10 |
| Decihenry | dH | 0.1 |
| Centihenry | cH | 0.01 |
| Millihenry | mH | 0.001 |
| Microhenry | µH | 1e-6 |
| Nanohenry | nH | 1e-9 |
| Picohenry | pH | 1e-12 |
| Femtohenry | fH | 1e-15 |
| Attohenry | aH | 1e-18 |
| Weber per ampere | Wb/A | 1 |
| Abhenry | abH | 1e-9 |
| EMU of inductance | EMU | 1e-9 |
| Stathenry | statH | 898,755,178,700 |
| ESU of inductance | ESU | 898,755,178,700 |
How to Use the Inductance Converter
- Type the inductance in the value box. Decimals and scientific notation such as 0.0025 or 2.5e-3 are accepted.
- Choose the From unit and the To unit.
- The result appears instantly, or press Convert Now. Very large or very small results are shown in scientific notation.
- Use Swap Units to reverse the conversion, Copy Result to copy the answer, open Show this value in all units for a full list, and Clear to start again.
Step-by-step by hand
- Find the size of each unit in the common base unit (H): 1 mH = 0.001 H and 1 µH = 1e-6 H.
- Divide the source size by the target size to get the conversion factor: 0.001 ÷ 1e-6 = 1,000, so 1 mH = 1,000 µH.
- Multiply by your value: 4.7 mH × 1,000 = 4,700 µH.
Inductance of a normal inductor cannot be negative, so only zero and positive numbers are accepted.
Common Inductance Conversions
- Millihenries to microhenries: 4.7 mH equals 4,700 µH and 0.0047 H.
- Switching converter: 10 µH equals 10,000 nH and 0.01 mH.
- RF coil: 220 nH equals 0.22 µH.
- PCB trace: 5 nH equals 5,000 pH.
- Large choke: 2 H equals 2,000 mH.
- CGS to SI: 1 abhenry equals 1 nH, and 1 stathenry equals 898,755,178,700 H.
Millihenry to Other Inductance Units
Quick reference for frequently used values
| mH | Henry (H) | Microhenry (µH) | Nanohenry (nH) |
|---|---|---|---|
| 0.001 | 1e-6 | 1 | 1,000 |
| 0.01 | 1e-5 | 10 | 10,000 |
| 0.1 | 0.0001 | 100 | 100,000 |
| 1 | 0.001 | 1,000 | 1,000,000 |
| 4.7 | 0.0047 | 4,700 | 4,700,000 |
| 10 | 0.01 | 10,000 | 10,000,000 |
| 100 | 0.1 | 100,000 | 100,000,000 |
| 1,000 | 1 | 1,000,000 | 1,000,000,000 |
Where and Why This Conversion Is Used
- Power electronics: choosing inductors for buck, boost and filter circuits, where datasheets use µH and mH.
- Radio and RF design: coils, matching networks and trace inductance in nH and pH.
- Audio: crossover coils and loudspeaker voice-coil inductance in mH.
- Power systems: reactors, transformers and line inductance in mH and H.
- Physics education: moving between SI henries and the CGS abhenry and stathenry.
Limitations
- The marked value is a nominal one. Real inductors have tolerances and their inductance changes with current as the core approaches saturation.
- Inductance in henries cannot be turned into stored energy without a current, or into impedance without a frequency.
Important Differences Between Related Electrical Measurements
- Inductance, H is flux per ampere. Magnetic flux, Wb is what is linked: 2 mH carrying 3 A links 6 mWb. Inductance is a property of the coil and does not change with the current in an ideal inductor.
- Inductance vs capacitance: an inductor stores energy in a magnetic field and opposes changes in current, so its impedance rises with frequency. A capacitor stores energy in an electric field and its impedance falls. Henries and farads are not interchangeable.
- Inductance vs reactance: reactance, in ohms, is X = 2π × f × L. It depends on frequency, whereas inductance does not.
- mH vs MH, pH vs PH: prefix case matters. mH is a thousandth of a henry, MH a million henries; pH is a trillionth of a henry, PH a thousand trillion.
Each converter on this site changes units within one quantity only, and none of them mixes quantities. The related tools are: Charge, Current, Linear Charge Density, Surface Charge Density, Volume Charge Density, Linear Current Density, Surface Current Density, Electric Field Strength, Electric Potential, Electric Resistance, Electric Resistivity, Electric Conductance, Electric Conductivity, Electrostatic Capacitance and Inductance.