Femtosiemens is 1e-15 siemens units.
Femtosiemens to Ronnasiemens Converter — fS to RS
Convert Femtosiemens (fS) to Ronnasiemens (RS) using the exact conversion factor (1 femtosiemens = 1e-42 ronnasiemens). See the formula, worked examples, and conversion table.
Femtosiemens to Ronnasiemens 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.
Ronnasiemens is 1e+27 siemens 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 Femtosiemens to Ronnasiemens
Femtosiemens and Ronnasiemens 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: Femtosiemens is 1e-15 siemens units, and ronnasiemens is 1e+27 siemens units.
Formula
ronnasiemens = femtosiemens × 1e-42
This factor comes from each unit's defined relationship to the category's base unit: 1 femtosiemens equals 1e-15 base units, and 1 ronnasiemens equals 1e+27 base units, so dividing one by the other gives the direct femtosiemens-to-ronnasiemens factor of 1e-42.
Simple example
1 fS × 1e-42 = 1e-42 RS
1 femtosiemens = 1e-42 ronnasiemens.
Real-world example
120 fS × 1e-42 = 1.2e-40 RS
120 femtosiemens = 1.2e-40 ronnasiemens.
Conversion table
| Femtosiemens (fS) | Ronnasiemens (RS) |
|---|---|
| 1 fS | 1e-42 RS |
| 5 fS | 5e-42 RS |
| 12 fS | 1.2e-41 RS |
| 24 fS | 2.4e-41 RS |
| 120 fS | 1.2e-40 RS |
| 240 fS | 2.4e-40 RS |
Reverse conversion: Ronnasiemens to Femtosiemens
1e-42 RS × 1e+42 = 1 fS
1e-42 ronnasiemens = 1 femtosiemens.
femtosiemens = ronnasiemens × 1e+42
For a page dedicated to this direction, see Ronnasiemens to Femtosiemens.
Understanding the Femtosiemens (fS)
Femtosiemens is 1e-15 siemens units.
Understanding the Ronnasiemens (RS)
Ronnasiemens is 1e+27 siemens units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many ronnasiemens are in 1 femtosiemens?
1 femtosiemens equals 1e-42 ronnasiemens, using the exact defined conversion factor rather than an estimate.
How do I convert femtosiemens to ronnasiemens?
Multiply the femtosiemens value by 1e-42. The converter above does this instantly to whatever precision you set.
How do I convert ronnasiemens back to femtosiemens?
Use the reverse factor: 1 ronnasiemens equals 1e+42 femtosiemens. You can also use the swap control in the converter above to flip the direction instantly.
What is a femtosiemens?
Femtosiemens (fS) is a unit of electricity.
What is a ronnasiemens?
Ronnasiemens (RS) is a unit of electricity.
Is the femtosiemens to ronnasiemens conversion exact?
Yes. Both femtosiemens and ronnasiemens 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.