Henry (H)
The henry (H) is the SI unit of inductance — one weber per ampere (Wb/A), the flux linkage per ampere of current.
Henries quantify inductor size in theory; practical inductors use millihenry, microhenry, and nanohenry.
Henry to Millihenry
Convert henry to millihenry instantly. Type in either field — results update live.
Instant
Private
Free
inductance Henry Millihenry
1 henry = 1,000 millihenrys
Unit
Unit
Conversion table
Selected H values converted to mH using the exact factor from this tool.
| H | mH |
|---|---|
| 0.01 | 10 |
| 0.1 | 100 |
| 1 | 1,000 |
| 2 | 2,000 |
| 3 | 3,000 |
| 5 | 5,000 |
| 10 | 10,000 |
| 20 | 20,000 |
| 50 | 50,000 |
| 100 | 100,000 |
| 1,000 | 1,000,000 |
How to convert
Exact conversion factors in both directions, plus a worked example.
1 H = 1000 mH
1 mH = 0.001 H
To convert henry to millihenry, multiply by 1000.
To convert millihenry to henry, multiply by 0.001.
Example: convert 10 H to mH
10 × 1000 = 10000 mH
About these units
Short background on the units used in this conversion.
Millihenry (mH)
The millihenry (mH) equals 0.001 henry — common for power inductors, chokes, and larger wound components.
Millihenries label power-supply inductors, filter chokes, and audio crossover coils.
Frequently asked questions
How many millihenrys are in one henry?
One henry equals 1,000 millihenrys. Multiply your henrys value by 1,000 to convert to millihenrys.
What is the conversion formula?
mH = H × 1,000The reverse is
H = mH × 0.001, using the same exact factors as this converter.Is this Henry to Millihenry converter private?
Yes. All calculations run locally in your browser. Nothing you type is sent to a server.