Rontoohm is 1e-27 ohm units.
Rontoohms to Femtoohms Converter — rOhm to fOhm
Convert Rontoohm (rOhm) to Femtoohm (fOhm) using the exact conversion factor (1 rontoohm = 1e-12 femtoohm). See the formula, worked examples, and conversion table.
Rontoohms to Femtoohms 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.
Femtoohm is 1e-15 ohm units.
Result = input x 1e-27 / 1e-15.
Electrical units in the same family convert directly.
Reserved above the conversion cards and below the converter.
About Converting Rontoohms to Femtoohms
Rontoohm and Femtoohm 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: Rontoohm is 1e-27 ohm units, and femtoohm is 1e-15 ohm units.
Formula
femtoohms = rontoohms × 1e-12
This factor comes from each unit's defined relationship to the category's base unit: 1 rontoohm equals 1e-27 base units, and 1 femtoohm equals 1e-15 base units, so dividing one by the other gives the direct rontoohm-to-femtoohm factor of 1e-12.
Simple example
1 rOhm × 1e-12 = 1e-12 fOhm
1 rontoohm = 1e-12 femtoohms.
Real-world example
120 rOhm × 1e-12 = 1.2e-10 fOhm
120 rontoohms = 1.2e-10 femtoohms.
Conversion table
| Rontoohm (rOhm) | Femtoohm (fOhm) |
|---|---|
| 1 rOhm | 1e-12 fOhm |
| 5 rOhm | 5e-12 fOhm |
| 12 rOhm | 1.2e-11 fOhm |
| 24 rOhm | 2.4e-11 fOhm |
| 120 rOhm | 1.2e-10 fOhm |
| 240 rOhm | 2.4e-10 fOhm |
Reverse conversion: Femtoohm to Rontoohm
1e-12 fOhm × 1e+12 = 1 rOhm
1e-12 femtoohms = 1 rontoohm.
rontoohms = femtoohms × 1e+12
For a page dedicated to this direction, see Femtoohm to Rontoohm.
Understanding the Rontoohm (rOhm)
Rontoohm is 1e-27 ohm units.
Understanding the Femtoohm (fOhm)
Femtoohm is 1e-15 ohm units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many femtoohms are in 1 rontoohm?
1 rontoohm equals 1e-12 femtoohms, using the exact defined conversion factor rather than an estimate.
How do I convert rontoohm to femtoohm?
Multiply the rontoohm value by 1e-12. The converter above does this instantly to whatever precision you set.
How do I convert femtoohm back to rontoohm?
Use the reverse factor: 1 femtoohm equals 1e+12 rontoohms. You can also use the swap control in the converter above to flip the direction instantly.
What is a rontoohm?
Rontoohm (rOhm) is a unit of electricity.
What is a femtoohm?
Femtoohm (fOhm) is a unit of electricity.
Is the rontoohm to femtoohm conversion exact?
Yes. Both rontoohm and femtoohm 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.