Rontowatt is 1e-27 watt units.
Rontowatts to Femtowatts Converter — rW to fW
Convert Rontowatt (rW) to Femtowatt (fW) using the exact conversion factor (1 rontowatt = 1e-12 femtowatt). See the formula, worked examples, and conversion table.
Rontowatts to Femtowatts 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.
Femtowatt is 1e-15 watt 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 Rontowatts to Femtowatts
Rontowatt and Femtowatt 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: Rontowatt is 1e-27 watt units, and femtowatt is 1e-15 watt units.
Formula
femtowatts = rontowatts × 1e-12
This factor comes from each unit's defined relationship to the category's base unit: 1 rontowatt equals 1e-27 base units, and 1 femtowatt equals 1e-15 base units, so dividing one by the other gives the direct rontowatt-to-femtowatt factor of 1e-12.
Simple example
1 rW × 1e-12 = 1e-12 fW
1 rontowatt = 1e-12 femtowatts.
Real-world example
120 rW × 1e-12 = 1.2e-10 fW
120 rontowatts = 1.2e-10 femtowatts.
Conversion table
| Rontowatt (rW) | Femtowatt (fW) |
|---|---|
| 1 rW | 1e-12 fW |
| 5 rW | 5e-12 fW |
| 12 rW | 1.2e-11 fW |
| 24 rW | 2.4e-11 fW |
| 120 rW | 1.2e-10 fW |
| 240 rW | 2.4e-10 fW |
Reverse conversion: Femtowatt to Rontowatt
1e-12 fW × 1e+12 = 1 rW
1e-12 femtowatts = 1 rontowatt.
rontowatts = femtowatts × 1e+12
For a page dedicated to this direction, see Femtowatt to Rontowatt.
Understanding the Rontowatt (rW)
Rontowatt is 1e-27 watt units.
Understanding the Femtowatt (fW)
Femtowatt is 1e-15 watt units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many femtowatts are in 1 rontowatt?
1 rontowatt equals 1e-12 femtowatts, using the exact defined conversion factor rather than an estimate.
How do I convert rontowatt to femtowatt?
Multiply the rontowatt value by 1e-12. The converter above does this instantly to whatever precision you set.
How do I convert femtowatt back to rontowatt?
Use the reverse factor: 1 femtowatt equals 1e+12 rontowatts. You can also use the swap control in the converter above to flip the direction instantly.
What is a rontowatt?
Rontowatt (rW) is a unit of electricity.
What is a femtowatt?
Femtowatt (fW) is a unit of electricity.
Is the rontowatt to femtowatt conversion exact?
Yes. Both rontowatt and femtowatt 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.