Inductance Converter
Convert inductance between henries, millihenries, microhenries, nanohenries, abhenries, and stathenries. Enter a value, then choose the units to convert from and to.
Convert Inductance Between Units
Inductance Conversion Formula
Where:
- \(L_{\text{from}}\) — the entered inductance in the selected From unit
- \(L_{\text{to}}\) — the converted inductance in the selected To unit
- \(f_{\text{from}}\) and \(f_{\text{to}}\) — the number of henries in one of each selected unit
The converter first expresses the entered value in henries, then divides by the henries-per-unit factor for the destination unit. This changes the unit, not the physical inductance.
Inductance Conversion – Calculation Example
Example: convert the default value of 1 henry (H) to millihenries (mH).
One henry equals 1 H, while one millihenry equals \(10^{-3}\) H:
\[L_{\text{to}}=1\times\frac{1}{10^{-3}}=1{,}000\ \text{mH}\]
Result: 1 H = 1,000 mH.
How to use the inductance converter
- Enter a nonnegative number in Inductance value. Use the number as written on your component, drawing, or specification.
- Choose its current unit in From unit.
- Choose the unit you need in To unit.
- Read Converted Inductance. Its unit symbol appears after the number. To check another conversion, change either unit or the entered value.
For example, to express an inductor labeled 470 µH in millihenries, enter 470, select Microhenry (µH) as the From unit, and select Millihenry (mH) as the To unit. The result is 0.47 mH.
What inductance measures
Inductance describes how a circuit element responds to a changing electric current. A changing current produces a changing magnetic field, which induces a voltage that opposes the change. Inductors and transformer windings are common examples of components for which inductance is an important specification.
The henry (H) is the SI derived unit of inductance. One henry corresponds to an induced voltage of one volt when current changes at one ampere per second, under the usual self-inductance convention. Component values are often much smaller than a henry, so datasheets commonly use millihenries (mH), microhenries (µH), or nanohenries (nH).
A larger number after conversion does not mean greater inductance: 1 H, 1,000 mH, and 1,000,000 µH describe the same value. Converting units helps align a datasheet value with the units used in a schematic or calculation. It does not determine how an inductor will perform in a particular circuit.
In AC analysis, inductive reactance depends on both inductance and frequency: \(X_L=2\pi fL\), with \(L\) expressed in henries. After converting a component value here, use a consistent frequency unit when working with the frequency converter. For quantities such as winding current or linked magnetic flux, see the electric current converter and magnetic flux converter.
Inductance units at a glance
Each factor below gives the number of henries in one unit. Multiply a value by its factor to express it in henries; divide a value in henries by the factor to obtain that unit.
| Unit | Symbol | Henries per unit |
|---|---|---|
| Henry | H | \(1\) |
| Millihenry | mH | \(10^{-3}\) |
| Microhenry | µH | \(10^{-6}\) |
| Nanohenry | nH | \(10^{-9}\) |
| Abhenry | abH | \(10^{-9}\) |
| Stathenry | statH | approximately \(8.98755179\times10^{11}\) |
Abhenry and stathenry are units from different CGS electromagnetic and electrostatic unit systems, respectively. One abhenry equals one nanohenry, although the names come from different systems. A stathenry is much larger than a henry; check the selected unit carefully when converting historical data.
Assumptions and practical limits
This is a unit converter, not an inductor model. It assumes that the number entered is an inductance value already known in the selected From unit. It does not account for winding resistance, core saturation, temperature, component tolerance, or changes in effective inductance with frequency and operating conditions. If a datasheet gives several inductance values under different test conditions, choose the one relevant to your application before converting it.
The converter uses approximately \(8.98755179\times10^{11}\) H per statH. Results involving stathenries therefore inherit that approximation. The displayed answer is also rounded to 10 decimal places: a very small nonzero result in H may appear as zero. If that happens, select a smaller destination unit, such as nH, to see a more useful number.
Keep prefixes and symbols distinct when copying a result. In particular, mH means millihenries and µH means microhenries; a factor of 1,000 separates them. For calculations using magnetic material properties, convert those quantities separately—for example, with the permeability converter—rather than treating inductance and permeability as interchangeable.
Frequently Asked Questions
How can I convert inductance units by hand?
Move three decimal places for each step between H, mH, µH, and nH. Going toward a smaller unit, multiply by 1,000; going toward a larger unit, divide by 1,000. For example, 2.2 mH is 2,200 µH or 0.0022 H. Write the unit beside each intermediate result to avoid reversing the conversion.
What is a normal or good inductance value for an inductor?
There is no universally good inductance value; it depends on the circuit. An RF circuit might use nanohenries or microhenries, while a power supply filter might use microhenries or millihenries. The number alone is not enough to choose a part: check its current rating, resistance, tolerance, and specified test conditions against your design requirements.
How do I measure an inductor’s inductance?
Use an LCR meter or an instrument with an inductance function, ideally with the component disconnected from the circuit. Set an appropriate test frequency and note whether the instrument reports series or parallel equivalent inductance. Readings can differ from a datasheet value because inductance may change with frequency, DC bias, or the connected circuit.
Can inductance be negative?
An ordinary passive inductor’s self-inductance is not negative, so a negative value is not appropriate for this unit converter. Negative signs can appear in equations for coupled coils because the polarity of mutual induction depends on winding orientation and the chosen voltage reference. A negative instrument reading can also indicate a measurement or model-setting issue rather than a physically negative self-inductance.
How do I combine inductors in series or parallel before converting units?
For uncoupled inductors, add their inductances in series. In parallel, add their reciprocals and take the reciprocal of the total; two equal inductors in parallel have half the inductance of either one. Convert every value to the same unit first. These rules need adjustment when coils are magnetically coupled, because their orientation and mutual inductance affect the result.
What do inductor markings such as 101 and 4R7 mean?
On inductors using a common microhenry marking scheme, 101 means 10 followed by one zero, or 100 µH, while 4R7 means 4.7 µH. Marking conventions vary by manufacturer and component type, however. Check the part number or datasheet before entering a marked value, especially if the package has no printed unit.