Millihenry is 0.001 henry units.
Millihenrys to Femtohenrys Converter — mH to fH
Convert Millihenry (mH) to Femtohenry (fH) using the exact conversion factor (1 millihenry = 1e+12 femtohenry). See the formula, worked examples, and conversion table.
Millihenrys to Femtohenrys converter
Converter
Electricity Converter
Convert electrical units by family and calculate voltage, current, resistance, power, and energy with context values.
Context values
Some unit families need one extra value for a physically accurate result.
Femtohenry is 1e-15 henry units.
Result = input x 0.001 / 1e-15.
Electrical units in the same family convert directly.
Reserved above the conversion cards and below the converter.
About Converting Millihenrys to Femtohenrys
Millihenry and Femtohenry both belong to the electricity family — voltage, current, resistance, power, or energy — units that show up constantly when working across the different standards used by household wiring (120V/240V depending on region), automotive electrical systems (12V/24V), and electronics design. Specifically: Millihenry is 0.001 henry units, and femtohenry is 1e-15 henry units.
Formula
femtohenrys = millihenrys × 1e+12
This factor comes from each unit's defined relationship to the category's base unit: 1 millihenry equals 0.001 base units, and 1 femtohenry equals 1e-15 base units, so dividing one by the other gives the direct millihenry-to-femtohenry factor of 1e+12.
Simple example
1 mH × 1e+12 = 1e+12 fH
1 millihenry = 1e+12 femtohenrys.
Real-world example
120 mH × 1e+12 = 1.2e+14 fH
120 millihenrys = 1.2e+14 femtohenrys.
Conversion table
| Millihenry (mH) | Femtohenry (fH) |
|---|---|
| 1 mH | 1e+12 fH |
| 5 mH | 5e+12 fH |
| 12 mH | 1.2e+13 fH |
| 24 mH | 2.4e+13 fH |
| 120 mH | 1.2e+14 fH |
| 240 mH | 2.4e+14 fH |
Reverse conversion: Femtohenry to Millihenry
1e+12 fH × 1e-12 = 1 mH
1e+12 femtohenrys = 1 millihenry.
millihenrys = femtohenrys × 1e-12
For a page dedicated to this direction, see Femtohenry to Millihenry.
Understanding the Millihenry (mH)
Millihenry is 0.001 henry units.
Understanding the Femtohenry (fH)
Femtohenry is 1e-15 henry units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many femtohenrys are in 1 millihenry?
1 millihenry equals 1e+12 femtohenrys, using the exact defined conversion factor rather than an estimate.
How do I convert millihenry to femtohenry?
Multiply the millihenry value by 1e+12. The converter above does this instantly to whatever precision you set.
How do I convert femtohenry back to millihenry?
Use the reverse factor: 1 femtohenry equals 1e-12 millihenrys. You can also use the swap control in the converter above to flip the direction instantly.
What is a millihenry?
Millihenry (mH) is a unit of electricity.
What is a femtohenry?
Femtohenry (fH) is a unit of electricity.
Is the millihenry to femtohenry conversion exact?
Yes. Both millihenry and femtohenry are defined by fixed standards rather than physical artifacts, so the factor of 1e+12 used above is exact to as many digits as you choose to display.
What's the difference between voltage, current, and resistance?
Voltage (volts) is the electrical potential difference driving current through a circuit. Current (amperes) is the rate of flow of electric charge. Resistance (ohms) is how much a component opposes that flow. They're related by Ohm's law (V = I × R), but they are distinct physical quantities, and this page converts between units of just one of them.