Femtowatt is 1e-15 watt units.
Femtowatts to Zeptowatts Converter — fW to zW
Convert Femtowatt (fW) to Zeptowatt (zW) using the exact conversion factor (1 femtowatt = 1,000,000 zeptowatt). See the formula, worked examples, and conversion table.
Femtowatts to Zeptowatts 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.
Zeptowatt is 1e-21 watt units.
Result = input x 1e-15 / 1e-21.
Electrical units in the same family convert directly.
Reserved above the conversion cards and below the converter.
About Converting Femtowatts to Zeptowatts
Femtowatt and Zeptowatt 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: Femtowatt is 1e-15 watt units, and zeptowatt is 1e-21 watt units.
Formula
zeptowatts = femtowatts × 1000000
This factor comes from each unit's defined relationship to the category's base unit: 1 femtowatt equals 1e-15 base units, and 1 zeptowatt equals 1e-21 base units, so dividing one by the other gives the direct femtowatt-to-zeptowatt factor of 1000000.
Simple example
1 fW × 1000000 = 1,000,000 zW
1 femtowatt = 1,000,000 zeptowatts.
Real-world example
120 fW × 1000000 = 120,000,000 zW
120 femtowatts = 120,000,000 zeptowatts.
Conversion table
| Femtowatt (fW) | Zeptowatt (zW) |
|---|---|
| 1 fW | 1,000,000 zW |
| 5 fW | 5,000,000 zW |
| 12 fW | 12,000,000 zW |
| 24 fW | 24,000,000 zW |
| 120 fW | 120,000,000 zW |
| 240 fW | 240,000,000 zW |
Reverse conversion: Zeptowatt to Femtowatt
1 zW × 1e-6 = 1e-6 fW
1 zeptowatt = 1e-6 femtowatts.
femtowatts = zeptowatts × 1e-6
For a page dedicated to this direction, see Zeptowatt to Femtowatt.
Understanding the Femtowatt (fW)
Femtowatt is 1e-15 watt units.
Understanding the Zeptowatt (zW)
Zeptowatt is 1e-21 watt units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many zeptowatts are in 1 femtowatt?
1 femtowatt equals 1,000,000 zeptowatts, using the exact defined conversion factor rather than an estimate.
How do I convert femtowatt to zeptowatt?
Multiply the femtowatt value by 1000000. The converter above does this instantly to whatever precision you set.
How do I convert zeptowatt back to femtowatt?
Use the reverse factor: 1 zeptowatt equals 1e-6 femtowatts. You can also use the swap control in the converter above to flip the direction instantly.
What is a femtowatt?
Femtowatt (fW) is a unit of electricity.
What is a zeptowatt?
Zeptowatt (zW) is a unit of electricity.
Is the femtowatt to zeptowatt conversion exact?
Yes. Both femtowatt and zeptowatt are defined by fixed standards rather than physical artifacts, so the factor of 1000000 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.