Attohenry is 1e-18 henry units.
Attohenrys to Henrys Converter — aH to H
Convert Attohenry (aH) to Henry (H) using the exact conversion factor (1 attohenry = 1e-18 henry). See the formula, worked examples, conversion table, history, and common uses.
Attohenrys to Henrys 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.
Henry is the SI unit of inductance.
Result = input x 1e-18 / 1.
Electrical units in the same family convert directly.
Reserved above the conversion cards and below the converter.
About Converting Attohenrys to Henrys
Attohenry and Henry 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: Attohenry is 1e-18 henry units, and henry is the SI unit of inductance.
Formula
henrys = attohenrys × 1e-18
This factor comes from each unit's defined relationship to the category's base unit: 1 attohenry equals 1e-18 base units, and 1 henry equals 1 base unit, so dividing one by the other gives the direct attohenry-to-henry factor of 1e-18.
Simple example
1 aH × 1e-18 = 1e-18 H
1 attohenry = 1e-18 henrys.
Real-world example
120 aH × 1e-18 = 1.2e-16 H
120 attohenrys = 1.2e-16 henrys.
Conversion table
| Attohenry (aH) | Henry (H) |
|---|---|
| 1 aH | 1e-18 H |
| 5 aH | 5e-18 H |
| 12 aH | 1.2e-17 H |
| 24 aH | 2.4e-17 H |
| 120 aH | 1.2e-16 H |
| 240 aH | 2.4e-16 H |
Reverse conversion: Henry to Attohenry
1e-18 H × 1e+18 = 1 aH
1e-18 henrys = 1 attohenry.
attohenrys = henrys × 1e+18
For a page dedicated to this direction, see Henry to Attohenry.
Understanding the Attohenry (aH)
Attohenry is 1e-18 henry units.
Understanding the Henry
Henry (H) measures electrical inductance. The SI derived unit of electrical inductance, equal to one volt-second per ampere. It is classified as a SI derived unit.
Where it's used: Universal — SI derived unit used worldwide
Uses of the Henry today
- Inductor and transformer ratings in electronics
- Motor and generator design calculations
- Circuit filtering and signal-processing design
History of the Henry
The henry is named after Joseph Henry (1797–1878), an American scientist who discovered the electromagnetic phenomenon of self-inductance independently of, and at roughly the same time as, Michael Faraday's related discoveries in England.
Historical origin. Henry was not the invention of a single named person; it developed through the process described above.
Henry — sources
- BIPM SI Brochure, 9th edition — Definition of the henry as a coherent SI derived unit.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many henrys are in 1 attohenry?
1 attohenry equals 1e-18 henrys, using the exact defined conversion factor rather than an estimate.
How do I convert attohenry to henry?
Multiply the attohenry value by 1e-18. The converter above does this instantly to whatever precision you set.
How do I convert henry back to attohenry?
Use the reverse factor: 1 henry equals 1e+18 attohenrys. You can also use the swap control in the converter above to flip the direction instantly.
What is a attohenry?
Attohenry (aH) is a unit of electricity.
What is a henry?
Henry (H) measures electrical inductance. The SI derived unit of electrical inductance, equal to one volt-second per ampere. It is classified as a SI derived unit.
Is the attohenry to henry conversion exact?
Yes. Both attohenry and henry are defined by fixed standards rather than physical artifacts, so the factor of 1e-18 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.