Inductance Conversion Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/10/2026
To convert an inductance, it is reduced to henries (H), then converted into the desired unit. Example: a 100 mH coil equals 0.1 H.
Explanation
The henry (H), the SI unit of inductance, measures a coil's ability to oppose a change in the electric current flowing through it, by generating an induced voltage proportional to that change. Since the henry is a fairly large unit for most coils used in everyday electronics, real components are most often expressed in submultiples: the millihenry (mH) for filtering or power-supply coils, and the microhenry (µH) for the smaller-value coils used at radio frequencies. This calculator converts between these scales using the henry as the pivot unit. Inductance pairs with capacitance in tuned circuits — see our LC resonant frequency calculator for how a coil and a capacitor together set a resonance, and our capacitance conversion calculator for the companion quantity.
Example: a 100 mH coil
Inputs
Value: 100. Starting unit: mH. Target unit: H.
Calculation
The "milli" prefix means 10⁻³: 100 mH = 100 × 10⁻³ H = 0.1 H.
Result
A 100 mH coil equals 0.1 H.
Frequently asked questions
Why are coils rarely expressed in raw henries?
Because an inductance of 1 henry is already a fairly large value, obtained in practice with bulky iron-core coils (like those in transformers). Most coils used in everyday electronics (filters, switching power supplies, radio-frequency circuits) fall between a few microhenries and a few hundred millihenries.
What is the difference between inductance and capacitance?
Inductance (in henries) opposes a change in CURRENT, while capacitance (in farads, see our capacitance conversion calculator) opposes a change in VOLTAGE. These two complementary behaviors are the basis of electronic filtering circuits, which often combine coils and capacitors.
How do I calculate the inductance of a coil I build myself?
This calculator converts a known inductance value between units; to calculate the resonant frequency a given coil produces with a capacitor, use our LC resonant frequency calculator.