A US fluid ounce is 1/128 of a US gallon.
Fluid ounces to Microliters Converter — fl oz to uL
Convert Fluid ounce (fl oz) to Microliter (uL) using the exact conversion factor (1 fluid ounce = 29,573.52956 microliter). See the formula, worked examples, conversion table, history, and common uses.
Fluid ounces to Microliters 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.
Microliter is 0.000001 liter units.
Result = input x 2.95735296e-5 / 1e-9.
Volume uses the cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Fluid ounces to Microliters
Fluid ounce and Microliter 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. Fluid ounce is most often used for us beverage container sizing (soda, water bottles).
Formula
microliters = fluid ounces × 29573.5295625
This factor comes from each unit's defined relationship to the category's base unit: 1 fluid ounce equals 0.0000295735295625 base units, and 1 microliter equals 1e-9 base units, so dividing one by the other gives the direct fluid ounce-to-microliter factor of 29573.5295625.
Simple example
1 fl oz × 29573.52956 = 29,573.52956 uL
1 fluid ounce = 29,573.52956 microliters.
Real-world example
10 fl oz × 29573.52956 = 295,735.2956 uL
10 fluid ounces = 295,735.2956 microliters.
Conversion table
| Fluid ounce (fl oz) | Microliter (uL) |
|---|---|
| 1 fl oz | 29,573.52956 uL |
| 5 fl oz | 147,867.6478 uL |
| 10 fl oz | 295,735.2956 uL |
| 25 fl oz | 739,338.2391 uL |
| 50 fl oz | 1,478,676.478 uL |
| 100 fl oz | 2,957,352.956 uL |
Reverse conversion: Microliter to Fluid ounce
1 uL × 0.0000338140227 = 0.000033814 fl oz
1 microliter = 0.000033814 fluid ounces.
fluid ounces = microliters × 0.0000338140227018
For a page dedicated to this direction, see Microliter to Fluid ounce.
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.
Understanding the Microliter (uL)
Microliter is 0.000001 liter units.
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 microliters are in 1 fluid ounce?
1 fluid ounce equals 29,573.52956 microliters, using the exact defined conversion factor rather than an estimate.
How do I convert fluid ounce to microliter?
Multiply the fluid ounce value by 29573.52956. The converter above does this instantly to whatever precision you set.
How do I convert microliter back to fluid ounce?
Use the reverse factor: 1 microliter equals 0.000033814 fluid ounces. You can also use the swap control in the converter above to flip the direction instantly.
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.
What is a microliter?
Microliter (uL) is a unit of volume.
Is the fluid ounce to microliter 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.
Where is the fluid ounce still used today?
United States (beverage, nutrition labeling)