Femtoampere is 1e-15 ampere units.
Femtoamperes to Ronnaamperes Converter — fA to RA
Convert Femtoampere (fA) to Ronnaampere (RA) using the exact conversion factor (1 femtoampere = 1e-42 ronnaampere). See the formula, worked examples, and conversion table.
Femtoamperes to Ronnaamperes 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.
Ronnaampere is 1e+27 ampere units.
Result = input x 1e-15 / 1e+27.
Electrical units in the same family convert directly.
Reserved above the conversion cards and below the converter.
About Converting Femtoamperes to Ronnaamperes
Femtoampere and Ronnaampere 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: Femtoampere is 1e-15 ampere units, and ronnaampere is 1e+27 ampere units.
Formula
ronnaamperes = femtoamperes × 1e-42
This factor comes from each unit's defined relationship to the category's base unit: 1 femtoampere equals 1e-15 base units, and 1 ronnaampere equals 1e+27 base units, so dividing one by the other gives the direct femtoampere-to-ronnaampere factor of 1e-42.
Simple example
1 fA × 1e-42 = 1e-42 RA
1 femtoampere = 1e-42 ronnaamperes.
Real-world example
120 fA × 1e-42 = 1.2e-40 RA
120 femtoamperes = 1.2e-40 ronnaamperes.
Conversion table
| Femtoampere (fA) | Ronnaampere (RA) |
|---|---|
| 1 fA | 1e-42 RA |
| 5 fA | 5e-42 RA |
| 12 fA | 1.2e-41 RA |
| 24 fA | 2.4e-41 RA |
| 120 fA | 1.2e-40 RA |
| 240 fA | 2.4e-40 RA |
Reverse conversion: Ronnaampere to Femtoampere
1e-42 RA × 1e+42 = 1 fA
1e-42 ronnaamperes = 1 femtoampere.
femtoamperes = ronnaamperes × 1e+42
For a page dedicated to this direction, see Ronnaampere to Femtoampere.
Understanding the Femtoampere (fA)
Femtoampere is 1e-15 ampere units.
Understanding the Ronnaampere (RA)
Ronnaampere is 1e+27 ampere units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many ronnaamperes are in 1 femtoampere?
1 femtoampere equals 1e-42 ronnaamperes, using the exact defined conversion factor rather than an estimate.
How do I convert femtoampere to ronnaampere?
Multiply the femtoampere value by 1e-42. The converter above does this instantly to whatever precision you set.
How do I convert ronnaampere back to femtoampere?
Use the reverse factor: 1 ronnaampere equals 1e+42 femtoamperes. You can also use the swap control in the converter above to flip the direction instantly.
What is a femtoampere?
Femtoampere (fA) is a unit of electricity.
What is a ronnaampere?
Ronnaampere (RA) is a unit of electricity.
Is the femtoampere to ronnaampere conversion exact?
Yes. Both femtoampere and ronnaampere are defined by fixed standards rather than physical artifacts, so the factor of 1e-42 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.