Zeptoliter is 1e-21 liter units.
Zeptoliters to Fluid ounces Converter — zL to fl oz
Convert Zeptoliter (zL) to Fluid ounce (fl oz) using the exact conversion factor (1 zeptoliter = 3.381402e-20 fluid ounce). See the formula, worked examples, conversion table, history, and common uses.
Zeptoliters to Fluid ounces converter
Converter
Volume Converter
Convert metric, US customary, imperial, cooking, dry, and industrial volume units.
Context values
Some unit families need one extra value for a physically accurate result.
A US fluid ounce is 1/128 of a US gallon.
Result = input x 1e-24 / 2.95735296e-5.
Volume uses the cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Zeptoliters to Fluid ounces
Zeptoliter and Fluid ounce appear side by side at fuel pumps and on beverage labels, since the US measures liquids in gallons while most of the world uses liters. Specifically: Zeptoliter is 1e-21 liter units, and a US fluid ounce is 1/128 of a US gallon.
Formula
fluid ounces = zeptoliters × 3.381402e-20
This factor comes from each unit's defined relationship to the category's base unit: 1 zeptoliter equals 1e-24 base units, and 1 fluid ounce equals 0.0000295735295625 base units, so dividing one by the other gives the direct zeptoliter-to-fluid ounce factor of 3.381402e-20.
Simple example
1 zL × 3.381402e-20 = 3.381402e-20 fl oz
1 zeptoliter = 3.381402e-20 fluid ounces.
Real-world example
10 zL × 3.381402e-20 = 3.381402e-19 fl oz
10 zeptoliters = 3.381402e-19 fluid ounces.
Conversion table
| Zeptoliter (zL) | Fluid ounce (fl oz) |
|---|---|
| 1 zL | 3.381402e-20 fl oz |
| 5 zL | 1.690701e-19 fl oz |
| 10 zL | 3.381402e-19 fl oz |
| 25 zL | 8.453506e-19 fl oz |
| 50 zL | 1.690701e-18 fl oz |
| 100 zL | 3.381402e-18 fl oz |
Reverse conversion: Fluid ounce to Zeptoliter
3.381402e-20 fl oz × 2.957353e+19 = 0.9999999201 zL
3.381402e-20 fluid ounces = 0.9999999201 zeptoliters.
zeptoliters = fluid ounces × 2.957353e+19
For a page dedicated to this direction, see Fluid ounce to Zeptoliter.
Understanding the Zeptoliter (zL)
Zeptoliter is 1e-21 liter units.
Understanding the Fluid ounce
Fluid ounce (fl oz) measures volume. The US fluid ounce is 1/128 of a US gallon: exactly 29.5735295625 milliliters. It is classified as a US customary unit.
Where it's used: United States (beverage, nutrition labeling)
Uses of the Fluid ounce today
- US beverage container sizing (soda, water bottles)
- US nutrition and medication dosing labels
History of the Fluid ounce
The US fluid ounce follows from the same English wine-gallon system as the rest of the US liquid volume units, defined as a consistent fraction of the gallon.
Historical origin. Fluid ounce was not the invention of a single named person; it developed through the process described above.
Fluid ounce — sources
- NIST Handbook 44, Appendix C — General tables of units including the US fluid ounce definition.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many fluid ounces are in 1 zeptoliter?
1 zeptoliter equals 3.381402e-20 fluid ounces, using the exact defined conversion factor rather than an estimate.
How do I convert zeptoliter to fluid ounce?
Multiply the zeptoliter value by 3.381402e-20. The converter above does this instantly to whatever precision you set.
How do I convert fluid ounce back to zeptoliter?
Use the reverse factor: 1 fluid ounce equals 2.957353e+19 zeptoliters. You can also use the swap control in the converter above to flip the direction instantly.
What is a zeptoliter?
Zeptoliter (zL) is a unit of volume.
What is a fluid ounce?
Fluid ounce (fl oz) measures volume. The US fluid ounce is 1/128 of a US gallon: exactly 29.5735295625 milliliters. It is classified as a US customary unit.
Is the zeptoliter to fluid ounce conversion exact?
Yes. The US fluid ounce is 1/128 of a US gallon: exactly 29.5735295625 milliliters. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.