A Zeptowatt (zW) equals 1e-21 watt(s), a scaled unit of electrical power used for zepto-scale electrical work.
Zeptowatts to Watts
Convert Zeptowatt (zW) to Watt (W) instantly with an exact formula, conversion table, and FAQ.
Reserved for a responsive leaderboard above the conversion details.
Professional calculator style
World-scale conversion engine
30+ categories
6,500+ units
Instant results
Offline ready
Electrical calculator
Electricity Converter
Convert zeptowatts (zW) to watts (W) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
The watt (W) is the SI unit of power, equal to one joule of energy transferred per second.
W = zW × 1.000000e-21
Results update instantly for Zeptowatts to Watts conversions.
Reserved above the conversion cards and below the converter.
Formula
W = zW × 1.000000e-21
zW = W × 1.000000e+21
Conversion table
| 1 zW | 1.000000e-21 W |
| 5 zW | 5.000000e-21 W |
| 10 zW | 1.000000e-20 W |
| 20 zW | 2.000000e-20 W |
| 50 zW | 5.000000e-20 W |
| 100 zW | 1.000000e-19 W |
| 500 zW | 5.000000e-19 W |
| 1000 zW | 1.000000e-18 W |
Related conversions
Reserved between the cards and the FAQ so the page stays balanced.
How the formula works
Both zeptowatt and watt measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in zeptowatts by 1.000000e-21 to get watts. To reverse the conversion, multiply a watt value by 1.000000e+21 to get back to zeptowatts.
Frequently asked questions
What is Zeptowatt (zW)?
A Zeptowatt (zW) equals 1e-21 watt(s), a scaled unit of electrical power used for zepto-scale electrical work.
What is Watt (W)?
The watt (W) is the SI unit of power, equal to one joule of energy transferred per second.
How do I convert zeptowatts to watts?
Multiply the zeptowatt value by 1.000000e-21 to get the equivalent in watts. For example, 5 zW × 1.000000e-21 = 5.000000e-21 W.
Is this conversion exact?
Yes. Both units use fixed, defined scale factors, so the factor 1.000000e-21 is an exact, non-rounded value.
Can I convert watts back to zeptowatts?
Yes. Divide the watt value by 1.000000e-21, or multiply it by 1.000000e+21, to get zeptowatts.
Reserved between the FAQ and the article so the page stays balanced.
About converting zeptowatts to watts
A Zeptowatt (zW) equals 1e-21 watt(s), a scaled unit of electrical power used for zepto-scale electrical work. The watt (W) is the SI unit of power, equal to one joule of energy transferred per second.
Use this calculator to move between zeptowatts and watts accurately for homework, engineering, billing, or everyday electricity calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.