Zeptowatt is 1e-21 watt units.
Zeptowatts to Attowatts Converter — zW to aW
Convert Zeptowatt (zW) to Attowatt (aW) using the exact conversion factor (1 zeptowatt = 0.001 attowatt). See the formula, worked examples, and conversion table.
Zeptowatts to Attowatts 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.
Attowatt is 1e-18 watt units.
Result = input x 1e-21 / 1e-18.
Electrical units in the same family convert directly.
Reserved above the conversion cards and below the converter.
About Converting Zeptowatts to Attowatts
Zeptowatt and Attowatt 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: Zeptowatt is 1e-21 watt units, and attowatt is 1e-18 watt units.
Formula
attowatts = zeptowatts × 0.001
This factor comes from each unit's defined relationship to the category's base unit: 1 zeptowatt equals 1e-21 base units, and 1 attowatt equals 1e-18 base units, so dividing one by the other gives the direct zeptowatt-to-attowatt factor of 0.001.
Simple example
1 zW × 0.001 = 0.001 aW
1 zeptowatt = 0.001 attowatts.
Real-world example
120 zW × 0.001 = 0.12 aW
120 zeptowatts = 0.12 attowatts.
Conversion table
| Zeptowatt (zW) | Attowatt (aW) |
|---|---|
| 1 zW | 0.001 aW |
| 5 zW | 0.005 aW |
| 12 zW | 0.012 aW |
| 24 zW | 0.024 aW |
| 120 zW | 0.12 aW |
| 240 zW | 0.24 aW |
Reverse conversion: Attowatt to Zeptowatt
0.001 aW × 1000 = 1 zW
0.001 attowatts = 1 zeptowatts.
zeptowatts = attowatts × 1000
For a page dedicated to this direction, see Attowatt to Zeptowatt.
Understanding the Zeptowatt (zW)
Zeptowatt is 1e-21 watt units.
Understanding the Attowatt (aW)
Attowatt is 1e-18 watt units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many attowatts are in 1 zeptowatt?
1 zeptowatt equals 0.001 attowatts, using the exact defined conversion factor rather than an estimate.
How do I convert zeptowatt to attowatt?
Multiply the zeptowatt value by 0.001. The converter above does this instantly to whatever precision you set.
How do I convert attowatt back to zeptowatt?
Use the reverse factor: 1 attowatt equals 1,000 zeptowatts. You can also use the swap control in the converter above to flip the direction instantly.
What is a zeptowatt?
Zeptowatt (zW) is a unit of electricity.
What is a attowatt?
Attowatt (aW) is a unit of electricity.
Is the zeptowatt to attowatt conversion exact?
Yes. Both zeptowatt and attowatt are defined by fixed standards rather than physical artifacts, so the factor of 0.001 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.