Inductance Converter – Convert H, mH, µH, nH, pH and More
The Inductance Converter is a free online tool that instantly converts inductance values between six standard units — from picohenries to kilohenries — covering the full range used in electronics, RF engineering, and power systems. Whether you are translating a coil specification from a data sheet, cross-checking inductor values between design tools, or studying electromagnetic theory, this converter delivers accurate results in real time with configurable decimal precision.
All conversions normalize through the Henry (H) as the SI base unit. Every cross-unit conversion follows the formula:
result = inputValue × (fromUnitFactor / toUnitFactor)
Because all six units use exact powers of 10 relative to the Henry, every conversion is mathematically precise within the limits of IEEE 754 double-precision arithmetic (approximately 15 significant digits). For very large or very small values the tool automatically switches to scientific notation.
Supported Inductance Units
The converter spans the complete practical range of inductance encountered in modern electronics, from sub-picohenry PCB parasitics to the multi-henry coils found in power equipment.
- Kilohenry (kH) — 10³ H — One thousand Henries; encountered only in very large power transformers and theoretical electromagnetic calculations. Rarely specified directly in component datasheets.
- Henry (H) — base SI unit — The SI unit of inductance, defined as Weber per Ampere (Wb/A). A conductor has 1 H of inductance when a current changing at 1 A/s induces an EMF of 1 V. Used in power factor correction inductors, large relay coils, and audio output transformers.
- Millihenry (mH) — 10⁻³ H — The most common unit for medium-frequency inductors. Audio crossover coils typically range from 0.1 mH to 10 mH; switching power supply filter chokes often fall between 1 mH and 100 mH.
- Microhenry (µH) — 10⁻⁶ H — Standard range for SMPS inductors operating above 100 kHz and for RF power inductors. A 4.7 µH shielded inductor is a common choice in DC-DC buck converters.
- Nanohenry (nH) — 10⁻⁹ H — Typical for chip inductors, RF matching networks, and antenna tuning circuits at VHF/UHF frequencies. PCB trace inductance runs roughly 1 nH per mm of trace length.
- Picohenry (pH) — 10⁻¹² H — Characterises parasitic inductance in IC bond wires, SMD component leads, and via holes. Relevant in gigahertz-frequency signal integrity analysis and microwave circuit design.
Conversion Examples
The following examples cover the most common inductance conversion scenarios:
- 4.7 mH → µH: 4.7 × (10⁻³ / 10⁻⁶) =
4700 µH(audio crossover coil specification) - 100 µH → mH: 100 × (10⁻⁶ / 10⁻³) =
0.1 mH(SMPS filter inductor to millihenry reference) - 1 H → mH: 1 × (1 / 10⁻³) =
1000 mH(power factor correction choke) - 33 nH → µH: 33 × (10⁻⁹ / 10⁻⁶) =
0.033 µH(RF matching network inductor) - 500 pH → nH: 500 × (10⁻¹² / 10⁻⁹) =
0.5 nH(bond wire inductance in a QFP package)
Inductance in Electronics and Circuit Design
Inductance is the property of an electrical conductor that opposes changes in current flow. When current through an inductor changes, the resulting change in magnetic flux induces a back-EMF proportional to the rate of change: V = L × (dI/dt), where V is the induced voltage in Volts, L is the inductance in Henries, and dI/dt is the rate of current change in Amperes per second.
In DC-DC converters, the inductor is the core energy-storage element. The inductance value determines the current ripple: a larger inductance reduces ripple current at a given switching frequency, improving efficiency but increasing physical size. Engineers routinely convert between µH and mH when comparing components from different suppliers.
In RF and microwave circuits, even a short PCB trace or component lead carries significant nanohenry or picohenry inductance at gigahertz frequencies. The impedance of an inductor scales as Z = 2πfL, so a 10 nH inductor presents approximately 628 Ω at 10 GHz — a value that dominates circuit behaviour unless carefully managed.
Inductance also determines the resonant frequency when paired with a capacitor: f = 1 / (2π√(LC)). This relationship underlies LC filters, oscillator tanks, and impedance-matching networks used across the frequency spectrum from audio to microwave.
Key Features of This Tool
- Instant real-time conversion — results update automatically as you type, with no button press required.
- Swap units — reverse the From/To direction with one click to immediately see the inverse conversion factor.
- Show all units — toggle on a complete reference table showing the input value simultaneously in all six inductance units.
- Adjustable precision — set decimal places from 0 to 10; the tool automatically uses scientific notation for extreme values.
- Negative value warning — displays a notice when a negative inductance is entered, flagging that the value is non-physical for passive components.
- Copy result — copy the converted value or the full all-units table to the clipboard with one click.